I have never owned a Windows Phone/Mobile device before, but I have daringly pre-ordered the Nokia Lumia 920. I did however get a copy of Windows 8 yesterday, and found a worrying thing:

The built-in Mail application only supports IMAP over legacy SSL (legacy port 993) and not the more modern and secure STARTTLS over standard IMAP port 143.

Does the Mail client in Windows Phone 8 suffer from the same limitations?


Based on my own experiences I have found the following:

Windows 8:

  • IMAP only SSL

Windows Phone 8:

  • SMTP only SSL

Incredibly inconvenient (for server administrators) and frankly astonishingly stupid and inconsistent. I would have believed the two clients shared at least some code in between them.

PS: I have not recorded the activity between the clients and servers. There could still be support through non-standard and totally undocumented quirks.


I have no experience with Windows Phone 8 myself yet, but the Windows Phone 7 IMAP4 settings only include checkboxes for "Require SSL" (one for incoming, one for outgoing email), and no port number settings. This could mean that just a fixed port number is possible, but I have not tried anything in this regard, so you might be able to use "host:port" syntax to do specify a different port number. No idea if this would work with STARTTLS though, sorry.

  • 2
    Port numbers can be included in the server name field, along with a non-standard bit to indicate whether SSL is enabled: [mailhost]:[port]:1 Sep 9 '15 at 6:50

Mail in Windows 10 and Outlook Mail (the same universal app under different branding) in Windows 10 Mobile will have STARTTLS support. Mail will still prefer SSL over TLS when available, however.

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