What Is an IMAP Server and How to Validate It
Before configuring email or starting migration, the most important question is: is the IMAP server actually working?
You can test it using: IMAP Server Validator
What Is IMAP
IMAP (Internet Message Access Protocol) allows you to access email stored on a server. Unlike POP3, messages stay on the server and synchronize across devices. Learn how IMAP is used in real migration → migration guide.
IMAP vs POP3
| Feature | IMAP | POP3 |
|---|---|---|
| Server storage | Yes | No |
| Multiple devices | Yes | Limited |
| Folder sync | Yes | No |
What Is an IMAP Server
- stores email messages
- allows remote access
- synchronizes folders
Examples:
- imap.gmail.com
- outlook.office365.com
- mx.sstmail.eu
Why Validate IMAP
- wrong hostname
- blocked ports
- TLS issues
- server offline
Validation helps detect these problems early. You can also analyze IP connectivity → IP diagnostic tool.
What the Validator Checks
- DNS resolution
- TCP connectivity
- TLS handshake
- IMAP greeting
- certificate details
Is It Safe
Yes. The validator does not require your password and only checks server response.
When Full Login Is Needed
- checking credentials
- testing permissions
- estimating mailbox size
👉 These checks are part of PostMaster migrations.
Conclusion
IMAP is the standard protocol for modern email systems. Validating your IMAP server before migration can prevent many common issues. To migrate email safely → PostMaster.