Email problem

[Carol Haynes]

I am a bit stumped by a problem for a client - anyone got any ideas

She uses MS Outlook from Office 365 to deal with email via IMAP

It sends and receives email fine everywhere EXCEPT in her own home. At home IMAP syncing appears to complete normally without error but nothing is actually synced.

I visited her home and deleted the IMAP account and set it up again from scratch  and it all worked fine while I was there but next day it wasn't working again.

She has satellite broadband (remote rural area) with a supplied modem and a bought router.

She is using Windows 8.1 with built in MS antivirus and firewall

Given that nothing else is behaving oddly at home I have no idea what is going on.

I have suggested rebooting all the network gear but she says she has done that.

Anyone any ideas? TIA

[Ath]

Does the router have an odd firewall rule that prohibits access to the Office 365 mail server?
Does the provider block access to that url? (next question could shed light on that)
Can Office 365 be accessed from a web-browser?
Does she have an entry in the hosts file blocking/redirecting Office 365 url's?

[Stoic Joker]

If it is connecting but not getting anything, it may be having issues inherent in a - high latency - satellite connection which are causing it to back off of the sync. Have you tried disabling cached mode to force it to get a fresh copy of everything each time it connects? That may make it easier to get an error - or see a real-time lag - if it having issues with the connection.

Other thoughts are along these lines.

[40hz]

Ran into that once with a client with a low end DSL connection in one of their remote offices. The additional latency caused multiple sync retries and the firewall which was set up for an adaptive (i.e. heuristic) response interpreted the constant multiple sync responses as a potential attack and shut off the port for 30 minutes thereby killing the sync. Half hour later the port would be reenabled and maybe sync would (or wouldn't) work for awhile until it started jackhammering repeat replies.

If it were a static firewall rule it wouldn't work at all - so the fact it worked and then stopped is a good indication that it's something other than a static rule at work.

I do know some ISP's get a little pissy if you're hitting their routers a little too frequently and rapidly. So they may also be throttling something or blocking a port.

In an attempt to cut down on junk mailers, one of the big providers in my area now insists on you only using their outbound SMTP servers. I first found out about that policy change when I got a dozen calls one morning from clients who suddenly could receive but not send any mail. Turns out the announcement was buried in the middle of an e-mail the ISP sent. You know. One of those marketing e-mails nobody ever reads?

The good part was that you could get a "waiver" of that requirement from this ISP. But you needed to call them and provide a justification for why you needed to do that first. Interfacing with your employer's e-mail system was usually deemed sufficient reason.

You could try calling the ISP to see if it might be on their end.