Email Settings GuideQuick answer: A1 mail uses securemail.a1.net for everything. IMAP is on 993 and POP3 on 995, each over SSL. Sending is SMTP on 587 with STARTTLS. Sign in with your full a1.net or aon.at address and your A1 email password. The one host covers both domains. Have a business address? It uses different servers.
What Changed Recently#
A1 puts every mail protocol on one secure host. Here is the current status and what an a1.net or aon.at address needs.
Worth knowing
One host does everything. securemail.a1.net answers for IMAP, POP3 and SMTP. There are no separate incoming and outgoing server names.
Worth knowing
a1.net and aon.at share the servers. The old aon.at addresses from A-Online run on the same securemail.a1.net as a1.net.
Worth knowing
A1 Business Mail is separate. Business accounts use their own hosts (bimap and bsmtp), not securemail.a1.net. This page covers consumer a1.net and aon.at mail.
Before You Begin#
Handle these two basics before anything else. Skip them and your email app will reject the connection even when every server value is correct.
1. An a1.net or aon.at address
Your address is you@a1.net or you@aon.at and the password is your A1 email password. You manage it in Mein A1.
Where: Mein A1
2. The one secure host
Enter securemail.a1.net for incoming and outgoing. The same host serves a1.net and aon.at.
Where: Find your settings →
About A1 Mail#
A1 is Austria largest telecom and its former national operator. A1 email covers a1.net and the older aon.at addresses, all on secure A1 servers.
A1 grew out of Telekom Austria and runs the country biggest network. The point to remember for email is that one host, securemail.a1.net, answers for IMAP, POP3 and SMTP alike, for both a1.net and the legacy aon.at addresses. You log in with the whole address and your A1 email password.
| Service Name | A1 Mail |
| Email Domains | a1.net, aon.at |
| Provider | A1 Telekom Austria |
| Secure Host | securemail.a1.net |
| SMTP Port | 587 STARTTLS |
| Email Type | a1.net, aon.at, such as you@a1.net |
| Password Reset | Mein A1 |
| Webmail | A1 Webmail |
| Protocols Supported | IMAP, POP3, SMTP |
| App Password Needed | No, mailbox password |
| Username | Full email address |
A1 Webmail Login#
You can always read your mail in a browser. The official sign in pages are:
Find Your Settings#
A1 fills the settings in for most apps. Every protocol connects to securemail.a1.net. Here are the exact values.
- Open your email app and add a new account.
- Choose IMAP on 993 or POP3 on 995.
- Set incoming to securemail.a1.net with SSL.
- Set outgoing to securemail.a1.net on 587 with STARTTLS.
A1 IMAP Settings#
IMAP is the incoming choice for most people. Mail stays put on the server, so a laptop and a phone read one shared inbox. The incoming host is securemail.a1.net over 993.
| IMAP Server | securemail.a1.net | |
| Port | 993 | |
| Encryption | SSL/TLS (required) | |
| Username | Your full address, including @a1.net or @aon.at | |
| Password | Your mailbox password | |
| Authentication | Required |
A1 POP3 Settings#
POP3 downloads mail to 1 device. Pick it only if you want a local copy on a single computer. Not sure? See the comparison below.
| POP3 Server | securemail.a1.net | |
| Port | 995 | |
| Encryption | SSL/TLS (required) | |
| Username | Your full email address | |
| Password | Your mailbox password |
A1 SMTP Settings#
SMTP handles outgoing mail. If you can read mail but not send it, the problem is here.
| SMTP Server | securemail.a1.net | |
| Port | 587 | |
| Encryption | STARTTLS (required) | |
| Username | Your full a1.net or aon.at address | |
| Password | Your A1 email password | |
| Authentication | Required. Turn on outgoing server authentication with a normal password. |
587 with SSL. Many home connections block port 25. A1 uses securemail.a1.net on 587 with STARTTLS. Confirm outgoing authentication is on.
Check A1 Settings Online#
You don't need to download anything to check A1 settings online. This page is the lookup: every value is verified, current and copyable straight from your browser. Not sure your address is an a1.net or aon.at one? Type it below to check in a moment.
Does my email address use these settings?
Runs in your browser only. Your address is never sent anywhere or stored.
Want to verify the account itself before configuring an app? Sign in at A1 Webmail, which confirms your address and password work. If webmail opens, any email app connects with the tables above.
Look Up IMAP Settings for Any Email Domain#
This page covers A1. For every other address, work email on a company domain included, we run a free online lookup database: imapsettings.com.
imapsettings.com
Complete email settings database, by Univik
Enter any email address and get the incoming and outgoing server settings for that domain in 1 step:
Your address is used only to find the settings for that domain. Nothing is stored or shared.
Username and Password#
Both come from your A1 account. The username is your full a1.net or aon.at address. The password is your A1 email password, which you manage in Mein A1. There is no separate app password.
Username is the full address
Type your full address in, with the part after the at sign. A bare mailbox name is turned down.
Put that same address on both incoming and outgoing.
Password is the mailbox one
This is your A1 email password, managed in Mein A1. Reset it there if an app keeps refusing it.
Your Mein A1 login guards billing and account settings, not the mailbox connection.
Set Up A1 in Email Clients#
The servers and ports are always the same. Only the menus differ. Jump to your app:
Outlook (Windows and Mac)
- In Outlook select Add Account, then turn on manual setup under Advanced options.
- Choose IMAP and set incoming to
securemail.a1.neton 993 with SSL. - Set outgoing to
securemail.a1.neton 587 with STARTTLS. - Enter the full address and mailbox password when Outlook prompts you.
- Send a test message to yourself to prove both paths.
Apple Mail (macOS)
- In Mail select Add Account, then pick Other Mail Account.
- Give your name, a1.net or aon.at address and password, then continue.
- Enter securemail.a1.net on incoming with SSL and outgoing on 587 with STARTTLS.
- Keep the SSL ports so nothing sends in plain text.
- Save and wait for the mailbox to load.
iPhone and iPad
- In Settings open Mail, then tap Mail Accounts and Add Account.
- Tap Other then Add Mail Account and fill your details.
- Keep IMAP chosen and put securemail.a1.net in both server boxes.
- Set outgoing to 587 with STARTTLS, since A1 sends on that port.
- Tap Save and let iOS run its check.
Android
- Open your mail app and tap Add account, then Other or IMAP.
- Put in your address and password. Switch to manual setup if it stalls.
- For incoming use securemail.a1.net on 993 over SSL.
- For outgoing use securemail.a1.net on 587 with STARTTLS.
- Save and swipe down to fetch your mail.
Thunderbird
- In Thunderbird pick Account Actions, then Add Mail Account.
- Type your name, a1.net or aon.at address and password, then Continue.
- Wait for detection, then make sure IMAP with SSL is picked.
- If detection fails, type securemail.a1.net in yourself for both.
- Hit Done and the folders fill in on the first sync.
A1 Webmail Settings#
Server settings connect your apps. These controls decide how the mailbox behaves on the server. They live in A1 Webmail, reached through webmail.a1.net.
Signature
Add one in the A1 Webmail preferences. It rides on mail sent from the browser. A desktop app keeps its own signature.
Vacation Auto Reply
Turn on an out of office reply in A1 Webmail. The server sends it, so it goes out even when your computer is off.
Filters and Folders
Build filters in A1 Webmail. A server side rule sorts a message before any device downloads it. An in app rule only runs while that app is open.
Spam and Blocked Senders
A1 screens incoming mail for spam. Block unwanted senders in A1 Webmail. Flagged mail lands in the junk folder for a look.
POP3 vs IMAP#
| Feature | IMAP | POP3 |
|---|---|---|
| Where mail lives | On the A1 server | Downloaded to 1 device |
| Multiple devices | ✅ Everything stays in sync | ❌ Each device sees different mail |
| Sent and deleted mail | ✅ Synced everywhere | ⚠️ Stays only on that device |
| Offline reading | ⚠️ Cached mail only | ✅ Full local copy |
| Server storage used | Yes, counts against your quota | Can be freed after download |
| Best for | Phone + computer, everyday use | Single PC, local archives |
A1 Servers at a Glance#
A few details are worth knowing before you set up an app. Here are the A1 server values in one place:
| Setup protocol | IMAP or POP3 |
| Login name | Full a1.net or aon.at address |
| Incoming host | securemail.a1.net (993 or 995) |
| Outgoing host | securemail.a1.net (587 STARTTLS) |
| Business Mail | Separate hosts bimap and bsmtp |
| Password reset | Mein A1 |
Troubleshooting A1 Connections#
Find the exact error your email app shows, then apply the fix:
| Error you see | What it means | Fix |
|---|---|---|
| Username or password rejected | Short username or wrong password | Use your full a1.net or aon.at address with your A1 email password from Mein A1. A bare mailbox name is turned down. |
| Cannot send on port 25 | ISP blocks the default SMTP port | Switch outgoing to securemail.a1.net on 587 with STARTTLS. The old port 25 is not for authenticated sending. |
| Insecure server warning | An old host or plain port was used | Older guides list pop.a1.net or mailbox.aon.at on ports 110 and 25. Use securemail.a1.net with SSL on 993 or 995 and STARTTLS on 587. |
| Business address will not connect | Business Mail is on other hosts | A1 Business Mail uses bimap.a1.net and bsmtp.a1.net, not securemail.a1.net. Consumer a1.net and aon.at addresses use securemail.a1.net. |
| Cannot connect to server | Wrong port or encryption | Set 993 with SSL incoming and 587 with SSL outgoing. A firewall on your own machine can block it as well. |
| Repeated password prompt | Short username or a typo | Clear the saved login, then put in the full address with the mailbox password. |
| Messages stuck in Outbox | SMTP authentication is off | Enable "outgoing server requires authentication" with the same login as incoming mail. |
| Business address will not connect | It was set to securemail.a1.net | A1 Business Mail uses bimap.a1.net, bpop.a1.net and bsmtp.a1.net on 993, 995 and 587. Sign in with the business address. |
| Business webmail link does not work | The consumer webmail was used | Business Mail webmail is businesswebmail.a1.net, a separate address from the consumer webmail.a1.net. |
Reader Reported Fixes
Use securemail.a1.net for both directions. Incoming and outgoing both point at the one secure host. If an app split the fields onto two different names, set them both to securemail.a1.net.
Test the login in webmail first. Sign in at webmail.a1.net with your address and password. If webmail opens, the credentials are right and the issue is in the app settings.
A1 Business Mail Uses Different Servers #
The settings above are for a personal a1.net or aon.at address. A business A1 address is a different product. It does not use securemail.a1.net at all. If a business mailbox will not connect on the consumer host, this is why.
A1 Business Mail runs on b-prefixed hosts. Incoming is bimap.a1.net on 993 for IMAP or bpop.a1.net on 995 for POP3, both over SSL. Outgoing is bsmtp.a1.net on 587 with STARTTLS and authentication on. The ports match the consumer side, so the only real change is the host name, where the b stands for business.
Sign in with your business email address and its password. The browser inbox is businesswebmail.a1.net, not the consumer webmail. A few business customers are on A1 hosted Exchange instead, which uses its own Outlook setup rather than these hosts, so check which product you have if the b-hosts do not fit.
| Item | What to know |
|---|---|
| Product | A1 Business Mail, not consumer |
| IMAP | bimap.a1.net on 993, SSL |
| POP3 | bpop.a1.net on 995, SSL |
| SMTP | bsmtp.a1.net on 587, STARTTLS |
| Webmail | businesswebmail.a1.net |
| Login | Your business email address |
| The tell | Hosts start with b, for business |
| Hosted Exchange | A separate A1 tier, own Outlook setup |
Moving Mail In or Out?#
A1 mail speaks plain IMAP, so a mailbox moves in or out like any standard account. Each folder stays on the server until the copy finishes.
Take a copy first. Back up the mailbox before a move. A note that arrives mid switch can sit on either side. A copy keeps you safe.
Carrying mail across? The Univik Email Migration Tool moves each folder over an IMAP link. Give it securemail.a1.net with your address and password on this side and the other account opposite.
Rather hand it off? Our Email Migration Services team runs the whole move and verifies each folder arrived.
Use These Settings in Univik Email Backup#
The same IMAP settings above let you download your complete A1 mailbox to your computer. Univik Email Backup saves everything as PST, MBOX, EML or PDF files you keep forever, even if the account closes.
- Download Univik Email Backup and install it on Windows.
- Select A1 from the source list. If A1 is not listed, pick a plain IMAP account.
- Give the complete email address with your mailbox password. The login name is always the whole email address.
- When the backup tool wants server details, hand it securemail.a1.net on port 993 with SSL. Take those values straight from the IMAP table above, with port
993over SSL. - Pick a saving format and folder, then start the backup. Large mailboxes download in the background.
Univik Tools That Use These Settings#
Many people land here while migrating or archiving a mailbox. All 3 tools use the same IMAP settings from this page:
Email Backup
Download your complete A1 mailbox to PST, MBOX, EML or PDF before switching or closing the account.
Email Backup Tool →
Email Migration Tool
Copy every folder from A1 straight into Gmail, Microsoft 365 or any other account. No manual export needed.
Email Migration Tool →
Email Converter Tool
Already have MBOX, EML or OST files from an old export? Convert them to PST, PDF or any format your new app opens.
Email Converter Tool →Prefer to hand the whole migration to experts?
If the hostnames and passwords feel like busywork, you can let the tool handle it. Univik's migration team handles the complete project: planning, transfer, verification and a report showing every folder made it. Since 2013, for single mailboxes up to full company moves.
Email Settings Glossary#
IMAP
Internet Message Access Protocol. Reads mail that stays on the server, so all your devices see the same inbox, folders and read status.
POP3
Post Office Protocol version 3. Downloads mail to 1 device and can remove it from the server. Older method, still useful for local archives.
SMTP
The protocol for sending mail. On A1 the outgoing host is securemail.a1.net on port 587 with STARTTLS.
SSL and STARTTLS
The encryption A1 uses. Incoming runs over SSL on 993 or 995. Outgoing runs over STARTTLS on 587.
A1 Email Password
The password for your a1.net or aon.at mailbox. You set or reset it in Mein A1. The same password opens A1 Webmail.
Mein A1
The A1 account portal where you manage your services and change your A1 email password.
A1 Webmail
The browser inbox for an a1.net or aon.at address, reached at webmail.a1.net. It uses the same address and password as your apps.
securemail.a1.net
The single secure host for consumer A1 mail. It answers for IMAP on 993, POP3 on 995 and SMTP on 587, for a1.net and aon.at alike.
aon.at
The legacy A-Online domain, now part of A1. An aon.at address still works and uses the same securemail.a1.net as a1.net.
A1 Business Mail
The separate A1 product for business accounts. It uses bimap.a1.net, bpop.a1.net and bsmtp.a1.net, not securemail.a1.net.
A1 Telekom Austria
Austria largest telecom and its former national operator. It provides a1.net and the older aon.at email on secure A1 servers.
One Host, Both Domains
A1 puts IMAP, POP3 and SMTP on a single host, securemail.a1.net, shared by a1.net and aon.at addresses.
bimap.a1.net
The IMAP host for A1 Business Mail on port 993 with SSL. The b marks the business server, apart from the consumer securemail.a1.net.
bsmtp.a1.net
The outgoing host for A1 Business Mail on port 587 with STARTTLS. Authentication must be on, using the business address and password.
businesswebmail.a1.net
The browser inbox for A1 Business Mail. It is a separate address from the consumer webmail.a1.net.
How We Verify These Settings#
Univik builds email backup, migration and converter software since 2013. Our tools sign in to A1 over IMAP and SMTP every day for thousands of users, so a changed server, port or login rule shows up in our connection logs before most guides notice it.
Every value on this page is confirmed with three checks: a live IMAP and SMTP connection from Univik Email Backup, a comparison against the A1 support pages and a sign in with a real mailbox using the full address. We re verify after any provider announcement and at least once a quarter.
Found something that no longer matches what A1 shows you? Tell us and we will retest and update the page, with the change logged in what changed recently.
Help & Support
Frequently Asked Questions
Incoming is securemail.a1.net on port 993 with SSL. Outgoing is securemail.a1.net on port 587 with STARTTLS. Sign in with your full a1.net or aon.at address and your A1 email password. One host covers both incoming and outgoing.
Two things catch people out. First, use your full a1.net or aon.at address as the username, not the part before the at sign. Second, the password is your A1 email password from Mein A1. Reset it in Mein A1 if an app keeps refusing it.
IMAP on securemail.a1.net 993 keeps your mail on the server, so a phone and a laptop share one inbox. POP3 on securemail.a1.net 995 downloads mail to one device and can remove the server copy, which suits a single machine or a local archive.
Yes. Every device uses securemail.a1.net on 993 for incoming and the same host on 587 for outgoing, with your full address and password. Only the menus differ.
Yes. Both run on securemail.a1.net with the same ports, IMAP on 993, POP3 on 995 and SMTP on 587. The aon.at addresses come from A-Online, now part of A1, so only your address differs. The host and password rules are identical.
Yes. A1 uses SSL on 993 and 995 with STARTTLS on 587, so your login and mail travel encrypted. Keep encryption switched on and avoid the old plain ports 143, 110 and 25, which send your login in the clear.
Point a backup tool at securemail.a1.net on 993 with SSL, using your full address and password. Let it copy every folder. The backup section walks through it. This keeps a local archive without removing mail from the server.
Often an old insecure setting or a password change. Move to securemail.a1.net with SSL on 993 or 995 and STARTTLS on 587, since the old pop.a1.net and mailbox.aon.at hosts on ports 110 and 25 are being retired. Reset your A1 email password in Mein A1 if needed.
Add your A1 address to the new account as an IMAP source with securemail.a1.net on 993. A migration tool that copies folder by folder works too. Both keep the mail on the A1 server until the copy finishes.
A business A1 address is a separate product and does not use securemail.a1.net. A1 Business Mail runs on bimap.a1.net for IMAP on 993, bpop.a1.net for POP3 on 995 and bsmtp.a1.net for SMTP on 587, all with the same encryption as the consumer side. Its webmail is businesswebmail.a1.net. Sign in with your business address. A few business customers use A1 hosted Exchange instead, which has its own Outlook setup. The section above covers it.
Other Email Provider Settings
Summary: A1 Settings at a Glance
- IMAP: securemail.a1.net, port 993, SSL/TLS
- POP3: securemail.a1.net, port 995, SSL/TLS
- SMTP: securemail.a1.net, port 587, STARTTLS
- Username is always your full email address
- A1 mailbox on your own server
- Pick IMAP for phone + computer sync
- Full address as the username
- Username is always the full email address