Office 365 IMAP settings

[BPretzel]

Hi,
I am having trouble with my IMAP office 365 settings.
Generally I use: outlook.office365.com STARTTLS (strict) 143 automatic authentication (incoming) / outlook.office365.com STARTTLS (strict) 587 automatic authentication (outgoing).

For the (public) wifi at work, I have to change the outgoing port (using "override when on wifi" option) to 25. (Obviously they block 143 which I understand is not uncommon)

This combination works well at work and at home (private network) and also on various other networks.

Information on the web for offcie365 says to use:
outlook.office365.com SSL port 993 (incoming) and smtp.office365.com TLS port 587 (outgoing) - but that does not seem to work (I have tried STARTTLS (strict) and STARTTLS (any) on 587 for outgoing as Aquamail does not have an explicit option for TLS). (I get "Persistent outgoing server network errors" and also "incomimg mail server (IMAP):Error connecting").

Now my query: on the network available on London Underground stations (Virgin media), I cannot connect to send or receive e-mails from the office365 account (gmail account, for instance, works fine) - despite having tried various combintations of the settings as described above. I also have the same account set up as EWS (defaults to "SSL (strict check), port 443 with authentication set to automatic or as "Prefer compatibility"). This works fine on my work public account and my private network (and several others) but again does not work on the London Underground network ("Account check error. Exchange mail server (EWS): Error connecting").

Do you (or anyone on the forum) have a list of other protocol / port combinations used by office365 that I could try? Blind random testing has got me nowhere to date and it is on the tube (when delayed at a station) that I am often trying to send e-mails...

I appreciate that this is nothing per se to do with AquaMail, but given your extensive knowledge of these things, I am hoping you may have some suggestions as it is all very frustrating!

Many thanks as always for any help.

With best wishes, Boris.

[Kostya Vasilyev]

I appreciate that you recognize how this issue isn't caused by AquaMail.

Can't comment on EWS -- it's basically "web browsing" and 443 is *the* standard port for HTTP... Shouldn't be a problem really, but I understand that it is sometimes...

Now, IMAP and SMTP... Sorry don't have a "just do this" solution.

* "STARTTLS" is what's called "TLS" in some other apps (and is called something else again in some other apps... the naming isn't always consistent).

It's "connect first, then enable encryption"

* "SSL" is "connect with encryption right away"

* port 143 + STARTTLS (TLS) is used for IMAP, that's incoming.

And you mentioned having to change the outgoing server. Doesn't make sense.

outlook.office365.com
STARTTLS
port 143

* port 993 + SSL is another, valid, standard, combo for encrypted IMAP (not just Office 365)

outlook.office365.com
SSL
port 993

* I am able to connect to outlook.office365.com using either way (993 + SSL or 143 + STARTTLS) from my home desktop computer, using low-level network testing tools.

* Outgoing:

Microsoft doesn't like using "SMTP + SSL + port 465" in their products (Office 365, Hotmail...)

They prefer using STARTTLS ("connect first, then enable encryption") and here you have the choice of using port 25 (commonly blocked) or port 587 (less so)

[Kostya Vasilyev]

And just FWIW... I was able to add my Office 365 account as IMAP / SMTP, and receive and send, with these settings:

IMAP (receiving):

outlook.office365.com
SSL (strict)
port 993

SMTP (sending):

outlook.office365.com
STARTTLS (strict)
port 587

[BPretzel]

Thanks for your helpful and informative reply.
Must be something they have set on the Virgin Mobile network (but I have not found others with similar problems). Just tried Outlook, which I guess uses active sync (it is not very configurable) and that works fine on the tube, as do my other email accounts, just not the office365 one which fails to connect...
Patience, patience... I'll try all the setting combinations again just to see.
Thanks again and very best wishes, Boris.

[Kostya Vasilyev]

"Just tried Outlook, which I guess uses active sync"

If you mean Outlook the mail app for Android, formerly called Accompli --

-- that's "cloud based", they pull your mail onto their own servers, and the actual Android app only needs to connect to those, not actual mail servers.

[BPretzel]

Oh - thanks for the tip.
So much for privacy!
Best wishes, Boris.