Email Settings GuideQuick answer: Rackspace Email uses one host, secure.emailsrvr.com, for everything. IMAP is port 993 with SSL/TLS. SMTP is port 465 (SSL) or 587 (STARTTLS). POP3 is port 995 with SSL. Sign in with your full email address and your mailbox password or an app password if you have MFA switched on.
What Changed Recently#
Email providers change login rules more often than server addresses. Here is the current status for Rackspace Email and what it means for your setup.
Latest update
Rackspace is steering customers toward Microsoft 365. Rackspace now offers self service and assisted tools to move mailboxes to Microsoft 365. Your secure.emailsrvr.com settings keep working until you actually migrate, so nothing breaks today.
Earlier change
Hosted Exchange was retired after the 2022 incident. Rackspace moved Hosted Exchange customers to Microsoft 365 following a security breach. Rackspace Email, the product on this page, is a separate IMAP service and still runs on secure.emailsrvr.com.
Earlier change
MFA changed how some accounts sign in. Rackspace Email supports multi factor authentication. With MFA on, mail apps need an app password rather than your normal mailbox password.
secure.emailsrvr.com and your mailbox password. Turn MFA on and you switch to an app password for apps.
Before You Begin#
Sort these 2 things out first. Miss them and your mail app will refuse to connect even with every server value correct.
1. Confirm it is Rackspace Email
Rackspace runs two email products. Rackspace Email signs in at apps.rackspace.com and uses the servers here. Hosted Exchange customers were moved to Microsoft 365 and need different settings.
Where: Tell them apart below →
2. Generate an app password if MFA is on
Without MFA your normal mailbox password works in apps. With MFA switched on, that password is rejected and you need an app password instead.
Where: App password steps below →
About Rackspace Email#
Rackspace Email is business email hosting from Rackspace Technology, run on the emailsrvr.com platform and used by companies on their own domains.
The one thing that trips people up: Rackspace runs two separate email products. Rackspace Email is the IMAP, POP and SMTP mailbox service on secure.emailsrvr.com that this page covers. Hosted Exchange was the Outlook and Exchange product, retired after a 2022 security incident and moved to Microsoft 365. Because Rackspace hosts your own company domain, your address is you@yourcompany.com rather than anything ending in rackspace.com.
| Service Name | Rackspace Email |
| Owned By | Rackspace Technology |
| Platform | Cloud Office (emailsrvr.com) |
| Email Domains | Your own business domain |
| Webmail URL | apps.rackspace.com |
| Protocols Supported | IMAP, POP3, SMTP |
| App Password Needed | Only when MFA is on |
| Mailbox Storage | 25 GB per mailbox |
secure.emailsrvr.com. Your own domain only changes the username, which is your full address, never the server. Were you moved to Microsoft 365 after Hosted Exchange? Use the Microsoft 365 guide instead.
Rackspace Webmail Login#
You can always read your mail in a browser. The official sign in pages are:
Webmail
Control Panel
Client Setup Tool
Which Rackspace Product?#
IMAP is already on, so there is nothing to enable. The real question with Rackspace is which of its two email products you have. Get this right first and the settings fall into place.
Rackspace Email (this page)
You sign in at apps.rackspace.com and your mail runs on secure.emailsrvr.com. This is the IMAP, POP and SMTP mailbox product. Every value on this page is for it.
Hosted Exchange (moved to 365)
The old Outlook and Exchange product was retired after a 2022 security incident. Those mailboxes moved to Microsoft 365. If that is you, follow the Microsoft 365 guide instead.
Rackspace IMAP Settings#
IMAP is the incoming protocol worth choosing. Mail is retained on the server, so each device presents an identical inbox.
| IMAP Server | secure.emailsrvr.com | |
| Port | 993 | |
| Encryption | SSL/TLS (required) | |
| Username | Your full email address, like you@yourcompany.com | |
| Password | Your mailbox password or an app password if MFA is on | |
| Authentication | Required |
Rackspace POP3 Settings#
POP3 brings mail onto a single device. Reasonable where one computer holds a local copy, otherwise not. Unsure? A comparison follows below.
| POP3 Server | secure.emailsrvr.com | |
| Port | 995 | |
| Encryption | SSL/TLS (required) | |
| Username | Your full email address | |
| Password | Your mailbox password or an app password if MFA is on |
Rackspace SMTP Settings#
secure.emailsrvr.com with SSL. Rackspace also runs unencrypted hostnames like imap.emailsrvr.com and smtp.emailsrvr.com, but the secure host on ports 993, 995, 465 and 587 is what you want. If your network blocks 465 and 587, Rackspace accepts outgoing mail on 8025 and 2525 as well.
SMTP handles outgoing mail. If mail comes in but will not go out, the problem is here.
| SMTP Server | secure.emailsrvr.com | |
| Port (SSL) | 465 | |
| Port (STARTTLS) | 587 | |
| Encryption | SSL or STARTTLS (required) | |
| Username | Your full email address | |
| Password | Same as incoming mail | |
| Authentication | Required. Outlook calls this the outgoing server authentication option. |
Check Rackspace IMAP Settings Online#
You don't need to download anything to check Rackspace IMAP settings online. This page is the lookup itself: every value is checked, current and copyable right in your browser. Because Rackspace hosts your own domain, the checker below routes known consumer domains to their own guides. For a business domain, confirm it uses secure.emailsrvr.com in your webmail or with your admin.
Will my address use these settings?
This runs entirely in your browser. Nothing about your address is sent or stored.
Want to confirm the account works before setting up an app? Sign in at Rackspace webmail, which confirms your address and password work. If MFA is on, confirm an app password exists. When both pass, any mail app connects using the tables above.
Look Up IMAP Settings for Any Email Domain#
This page covers Rackspace Email. 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.
Rackspace App Password Setup#
The most common setup failure is using the wrong password. Here is which one works where:
| Where you sign in | Regular password | App password |
|---|---|---|
| Rackspace webmail and control panel | ✓ Works | ✗ Not needed |
| Outlook, Apple Mail, Thunderbird without MFA | ✓ Works | ✗ Not needed |
| Outlook, Apple Mail, Thunderbird with MFA on | ✗ Rejected | ✓ Required |
| Migration and backup tools with MFA on | ✗ Rejected | ✓ Required |
How to Generate an App Password
- Turn on multi factor authentication first if you have not. App passwords only exist once MFA is on.
- Open your account security settings in Rackspace webmail or the Cloud Office control panel.
- Find the app passwords area and create a new one.
- Label it for the app it serves, something like Outlook or iPhone Mail, then confirm.
- Copy the generated password and paste it in your email app in place of your mailbox password.
Set Up Rackspace in Email Clients#
Most apps will not auto detect Rackspace, so pick manual setup and enter secure.emailsrvr.com by hand. The servers never change.
Jump to your app:
Outlook (Windows and Mac)
- Open Outlook → File → Add Account (in new Outlook, Settings → Accounts → Add account).
- Enter your Rackspace address, open Advanced options and check "Let me set up my account manually".
- Choose IMAP and enter
secure.emailsrvr.comport993(SSL) for incoming andsecure.emailsrvr.comport587(STARTTLS) for outgoing. - Enter your mailbox password or an app password if MFA is on.
- Finish, then email yourself to confirm sending and receiving both work.
Apple Mail (macOS)
- Open Mail → Settings → Accounts → Add Account → Other Mail Account.
- Enter your name, Rackspace address and password, then continue.
- When detection fails, enter
secure.emailsrvr.comas both the incoming and outgoing server. - Set incoming to IMAP 993 SSL and outgoing to 465 SSL, with the same login.
- Tick Mail in the list and finish.
iPhone and iPad
- Open Settings → Apps → Mail → Mail Accounts → Add Account → Other.
- Tap Add Mail Account and enter your name, address and password.
- Keep IMAP selected. Enter
secure.emailsrvr.comfor both incoming and outgoing. - Use 993 SSL incoming and 465 SSL outgoing, with your full address as the username.
- Choose Save and allow iOS a moment to confirm the account.
Android
- Start the Android mail app you use and pick Add account.
- Choose Other (IMAP) since Rackspace is not in the list.
- Enter your address and password, then pick Manual setup.
- Enter the servers:
secure.emailsrvr.com993 SSL incoming,secure.emailsrvr.com465 SSL outgoing. - Complete setup and pull to refresh your inbox.
Thunderbird
- Inside Thunderbird, take Account Settings, then Account Actions, then Add Mail Account.
- Enter your name, Rackspace address and password, then select Continue.
- Choose Configure manually. Thunderbird rarely detects Rackspace on its own.
- Set both servers to
secure.emailsrvr.com, IMAP 993 SSL and SMTP 465 SSL, with your full address. - Select Done. Folders sync on first open.
Rackspace Webmail Settings#
Server settings connect your apps. These settings control how Rackspace mail itself behaves. All of them live in webmail at apps.rackspace.com under Settings.
Signature
Settings, then Signature. A signature set here applies to webmail alone. Outlook and other clients maintain separate ones of their own.
Vacation Auto Reply
Settings, then Auto-Reply. Give it a start and an end date so it stops without prompting. It runs on Rackspace's servers, so replies continue with your computer shut down.
Filters and Folders
Settings, then Filtering. Rules created here execute on the server, filing mail before your phone or Outlook collects it. A rule held inside a client only runs while that client is open.
Spam and Blocked Senders
Settings, then Spam Settings. Individual senders or entire domains can go on the block list. Blocked mail is filed to the Spam folder instead of the inbox.
POP3 vs IMAP#
| Feature | IMAP | POP3 |
|---|---|---|
| Where mail lives | On the Rackspace 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 |
Rackspace Sending and Storage Limits#
Hit a limit and Rackspace blocks sending for the rest of the day. Rackspace counts recipients, not messages, so know the numbers before you bulk send or migrate:
| Daily sending limit | 10,000 recipients per 24 hours, per address |
| How it is counted | By recipient, not by message |
| Message and attachment size | 50 MB total |
| Mailbox storage | 25 GB per mailbox |
| Group list external recipients | 250 maximum |
| What happens at the limit | Sending blocked until the 24 hour window resets |
Troubleshooting Rackspace Connections#
Find the exact error your email app shows, then apply the fix:
| Error you see | What it means | Fix |
|---|---|---|
| Login or authentication failed | MFA is on, so the mailbox password is rejected | Generate an app password and use it in place of your password. If MFA is off, re-check your full address and mailbox password. |
| Nothing connects after a move to Microsoft 365 | You had Hosted Exchange, not Rackspace Email | Your mailbox is now on Microsoft 365. Use the Microsoft 365 settings, not secure.emailsrvr.com. |
| Cannot connect to server | Wrong host, port or encryption | The host is secure.emailsrvr.com for both directions. Use IMAP 993 SSL and SMTP 465 or 587. Antivirus software and VPN clients are also known to block these ports. |
| Username not accepted | A short name was entered | Rackspace usernames are the full email address, like you@yourcompany.com. A short login name will not connect. |
| Cannot send on port 465 or 587 | Your network blocks the standard SMTP ports | Rackspace also accepts outgoing mail on 8025 and 2525. Switch the outgoing port to one of those and keep the same host. |
| Messages stuck in Outbox | SMTP authentication is off | Enable outgoing authentication and point it at the same credentials as incoming. |
Reader Reported Fixes
Two fixes that come up again and again in Rackspace setups, beyond the error table above.
Point both servers at the same host. Rackspace uses secure.emailsrvr.com for incoming and outgoing. People sometimes invent an smtp. version of the hostname and sending fails. There is only one host. It handles both.
Check MFA before blaming the password. If mail worked then stopped after a security change, MFA was likely switched on. The mailbox password no longer works in apps. Generate an app password and paste that in.
Moving off Rackspace?#
Many Rackspace customers are moving to Microsoft 365. Rackspace itself pushes that path. You have a few ways to do it.
Use Rackspace's own tools. The Cloud Office control panel has a self service migration tool. Rackspace also offers assisted migration to Microsoft 365. Both need the mailbox address and password for every account.
Prefer a direct folder by folder copy? The Univik Email Migration Tool moves mail straight from Rackspace to any destination. Enter secure.emailsrvr.com with a mailbox or app password on the Rackspace side and your new provider on the other.
Back up before you switch. Save the mailbox first so you keep a copy no matter how the move goes.
Rather not do it yourself? Our Email Migration Services team designs the transfer, runs it through, then checks each folder arrived.
Use These Settings in Univik Email Backup#
The IMAP settings above also let you pull your whole Rackspace mailbox down to your computer. Univik Email Backup writes the whole mailbox to PST, MBOX, EML or PDF that stays yours even after the account closes.
- Obtain Univik Email Backup and install it under Windows.
- Select IMAP from the source list. Rackspace is not usually named, so IMAP is the right choice.
- Sign in using the full email address together with your app password. The ordinary password is refused here as well.
- If the tool asks for server details, use
secure.emailsrvr.comwith port993and SSL from the IMAP table above. - Choose a save format and folder, then start the backup. Bigger mailboxes keep downloading in the background.
Univik Tools That Use These Settings#
Readers often arrive here midway through a migration or an archive. All 3 tools take the IMAP values above:
Email Backup
Download your complete Rackspace mailbox to PST, MBOX, EML or PDF before switching or closing the account.
Email Backup Tool →
Email Migration Tool
Copy every folder from Rackspace straight into Microsoft 365, Gmail 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?
There is no obligation to master any of this yourself. Univik's migration team owns the project from end to end, scoping, transferring, verifying, then supplying a report of where every folder came to rest. Operating since 2013, across single mailboxes and full company moves alike.
Email Settings Glossary#
IMAP
Internet Message Access Protocol. Reads mail retained on the server, holding inbox, folders and read marks in agreement across devices.
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
Simple Mail Transfer Protocol. Sends your outgoing mail. Every account needs it next to IMAP or POP3, which only receive.
SSL / TLS / STARTTLS
Encryption for the connection. SSL/TLS encrypts from the start (ports 993, 995, 465). STARTTLS upgrades a plain connection (port 587).
App Password
A 16 character code used in place of your real password inside an app. Its merit is that a single app can be revoked without touching your main password.
OAuth
Signing in through the provider's own window instead of giving the app a password. Most large providers have been moving this way.
How We Verify These Settings#
Univik has built email backup, migration and converter software since 2013. Our tools sign in to Rackspace 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 3 checks: a live IMAP and SMTP connection from Univik Email Backup, a comparison against Rackspace's official documentation and a test against the current webmail and control panel. We re verify after any Rackspace announcement and at least once a quarter.
Found something that no longer matches what Rackspace shows you? Let us know and we will retest, refresh the page and log it in what changed recently.
Help & Support
Frequently Asked Questions
Both use one host, secure.emailsrvr.com. IMAP is port 993 with SSL. SMTP is port 465 with SSL or 587 with STARTTLS. Sign in with your full email address and your mailbox password or an app password if MFA is on.
Two common causes. If MFA is on, the mailbox password is blocked in apps, so generate an app password and use that. If MFA is off, check that your username is the full email address, not a short name.
IMAP. Rackspace itself advises against POP because a wrong POP setup can delete server copies after 14 days. IMAP keeps your phone, computer and webmail in sync. Full comparison here.
Only if you turned on multi factor authentication. Without MFA, your normal mailbox password works in every app. With MFA on, apps need an app password instead, while your normal password still works in webmail.
No. App passwords show only once. Delete the old one in your Rackspace security settings and generate a new one. It takes under a minute and does not affect your other apps.
Yes. Use secure.emailsrvr.com with SSL. If you have MFA on, add an app password. Turning MFA on is the single best way to protect a business mailbox. App passwords let you revoke one app without changing your main password.
An IMAP client fetches mail as it syncs, whereas a dedicated backup tool runs faster and writes standard files that open anywhere. See how to back up your Rackspace mailbox. This matters most before a move to Microsoft 365, so you keep a copy no matter how the migration goes.
Two likely reasons. Someone turned on MFA, so the mailbox password now needs an app password. Or your mailbox was a Hosted Exchange account moved to Microsoft 365, which uses different servers. Check what changed recently.
An email migration tool copies mail directly between the 2 accounts over IMAP. You need the Rackspace IMAP settings with your mailbox or app password for this side, plus the destination account details. Rackspace also has its own self service tool for moves to Microsoft 365.
Where the stakes are high or the mailbox count is, our managed email migration service covers the whole job.
Other Email Provider Settings
Summary: Rackspace Settings at a Glance
- One host: secure.emailsrvr.com for everything
- IMAP port 993, POP3 995, both SSL/TLS
- SMTP port 465 (SSL) or 587 (STARTTLS)
- Username is your full email address
- App password only when MFA is on
- Pick IMAP, Rackspace advises against POP
- Sending limit: 10,000 recipients per day
- Mailbox storage: 25 GB per mailbox