I recommend checking our FAQ's where you can find settings for most common providers and other suggestions. Let us know whether they were helpful.
I am running AVG [free] 2013 and use Outlook Express with XP-SP3 as my o/s.
My email incoming is a POP3 and outgoing [SMTP] is an IMAP.
I have noticed on several occasions that when I reply or send an email that the email scanner [outgoing] activates and I get an error message telling me my server has been idle to long and unable to send.
Sometimes the email sits in my outbox for 2-3 days. I have contacted my service provider and they advise me that there may be some issues with the IMAP protocol and they are 'working on it'. This was 4 months ago.
However, the email gets sent most of the time and then gets blocked.
Tonight, I disabled AVG temporarily and the email got sent.
This tells me the problem is not with my ISP but rather with the outgoing email part of AVG.
Is there a workaround for this or can I just send my email out, unscanned which is not normal as ALL AV have email scanners that scan and certify both incoming and outgoing email.