I have a problem with sending emails which I believe is caused by my Kerio 4 firewall.
I am using Kerio 4.1.2, together with Norton Antivirus 2002 with latest updates. For my email client I use Mozilla Thunderbird, but the problem also occurs with MS Outlook.
When I send an email it seems to go out, and Norton AV scans it - but then Norton cannot get it past the firewall and comes up with an error message.
I then have to retrieve the email from the "sent" folder and repost it. It _always_ succeeds the 2nd time.
When I disable Kerio I don't have this problem, which makes me suspect the firewall. I don't have the problem with short one line emails.
I do not suspect the firewall SMTP settings because these work okay the 2nd time round.
I also seem to have a similar problem with posting a newsgroup item like this, and in posting to web forums - these frequently need more than one go to succeed - but not every time like with email.
I have posted this problem to the Kerio site forum with no replies.
TIA Johnie.