Email has one unusual property among widely used communication systems: the standards are open and old, and they still work. SMTP sends mail and IMAP reads it. Any client that speaks those protocols can connect to any compliant server, and you can move your mail from one provider to another without asking anyone's permission. Proprietary APIs offer more features, but each one is a dependency on a single vendor's rules, quotas and roadmap.
What IMAP gives you
IMAP, the Internet Message Access Protocol, lets a client read, search, flag and organise messages that stay on the server. The current revision, IMAP4rev2, is specified in RFC 9051. Its predecessor, IMAP4rev1, has been implemented for decades, and mainstream clients on every platform support it. Thunderbird, Apple Mail, K-9 Mail, aerc and mutt all use it. The same account can be read from a desktop client, a phone and a terminal, with the server as the single source of truth.
IDLE, defined in RFC 2177, lets a client wait for the server to announce new messages instead of polling. Combined with TLS, it gives you timely delivery without a vendor-specific push service.
What proprietary APIs add, and what they cost
Vendor APIs often provide things IMAP does not: labels in place of folders, threaded conversation objects, server-side search that understands a provider's own concepts, and integrations with calendars and office suites. Those features are useful. The cost appears in four places.
- Data model. Labels, categories and conversation IDs do not map cleanly to folders. Moving to another provider means reinterpreting your organisation, and some information does not survive the trip.
- Access rules. API access usually requires a registered application, an OAuth consent flow and quotas that the vendor can change. A tool that worked last year can stop working after a policy update.
- Ecosystem. Integrations are built against one vendor's SDK. Each new service asks for its own permission, and the more you use, the harder it is to leave.
- Export. A vendor's export may be a proprietary archive, a partial data set, or a long-running job. Standard IMAP lets you copy the whole mailbox with any compliant tool.
Standard and alternative protocols
IMAP is not the only open option. JMAP, specified in RFC 8620 and RFC 8621, is a newer protocol designed around JSON and HTTP, with better support for batching and push. Its client base is growing but still small, and most providers still expose IMAP as the default. SMTP, specified in RFC 5321, remains the transport for sending. Authentication has moved toward OAuth 2.0 for some providers, through the XOAUTH2 SASL mechanism, while app passwords serve clients that cannot do the OAuth dance.
Connecting to ITProMail with standard tools
Mail clients connect to ITProMail with ordinary settings. Use the same values in any IMAP client:
| Setting | Value |
|---|---|
| IMAP server | imap.itpromail.com, port 993, TLS |
| SMTP submission | smtp.itpromail.com, port 465 (TLS) or 587 (STARTTLS) |
| Username | Your full email address |
| Password | An app password created under Account > Security |
Use an app password for each client rather than your login password, so you can revoke one device without disturbing the rest. The app password list lives under Account > Security, alongside two-factor settings and active sessions. Step-by-step client guides are in the IMAP and SMTP documentation and the app passwords guide.
Keeping your mail portable
IMAP portability is only real if you use it. A few habits keep the option open:
- Use folders as you would in any mail system, and avoid relying on server-specific tags for anything you cannot recreate.
- Keep a periodic local copy of the mailbox, as covered in backing up your mailbox.
- Test a migration with a dry run before committing. The imapsync import guide describes the approach.
- Prefer clients that store mail in standard formats, so your local copy is readable without the client that created it.
Open protocols are not a guarantee of convenience. They do guarantee that the choice of provider, client and tool stays yours. For a mailbox you expect to keep for years, that is the feature that matters most.