I am having intermittent but serious problems with my email that began when I received a message from BT that they had 'detected suspicious activity' on my account and forced me to reset my email passwords. Of course this also involves the fiddly process of resetting the POP and SMTP passwords in the mail programme.
However, this whole rigmarole left my accounts completely unresponsive and offline. Trying to talk to BT's Helpdesk in India didn't help (of course) but the problem appeared to clear up of its own accord a few hours later. Unfortunately I discovered this was an illusion, as on Tuesday I realised that I had dozens of unsent emails in my outbox.
I therefore went through the whole process again yesterday, resetting the email passwords, with the same sort of result - the issue appears to clear after a few hours but I am having to check each email to ensure it is being sent, and wondering whether I am not receiving incoming emails.
I'm now assuming that BT cannot or will not help and searching for a provider with call centre staff that a) speak English fluently and b) know something about the issues they are being asked to resolve. I am not trying to throw in cheap digs here, it is a significant hurdle when trying to resolve problems if you can't communicate properly, and if the staff in question only know very basic stuff. I use my email for my work, and this is costing me clients...
Use this link to check the settings on your Mac. Some Posters reported problems when they used capitals in their password. They found that by only using small case and numbers it resolved their problem. It might be worth trying.