Antispam is blocking outgoing email in Thunderbird

[Ragus]

HI
I am trialling avast internet security 7 for a few days now.  I notice that when I start my email client, Thunderbird 13.0.1, Avast IS appears to block my connection to the two SMTP servers that I use and prevents me from sending emails.   I have the email scanner turned off for outgoing emails.  By turning off and on various modules I tracked down the problem to the antispam module - if I turn this module on, the connection to the SMTP servers is blocked and no emails can be sent; if I turn it off everything is fine.  Does anyone know why this is happening and what the solution is (other than to keep the antispam module off)?
Thanks for any ideas.

[DavidR]

What errors are being displayed ?

If they relate to SSL connection - avast! 6.x, 7.x: SSL Problems The Mail Shield may not scan some e-mails - see https://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=842. Whilst this is an old article and mentions avast6 it is relevant for avast7 also.

It shouldn't be the anti-spam module, more like the Mail Shield (why I asked for any errors) as I'm not sure at what point the anti-spam module does its checks and if that is limited to inbound email not outbound. These are assumptions on my part, not using the versions of avast that contains the anti-spam module.

Have (or did) you another Anti-Virus installed in this system, if so what was it and how did you get rid of it ?

[Ragus]

Hi DavidR

Thanks for replying. I agree that logically one would have thought the problem was with Mail Shield (in fact it was the first thing I tried turning off) but it is definitely with AntiSpam.  I can replicate the error every time without fail by turning on AntiSpam module with all other modules on.  The error message is:
   
"An error occurred sending mail: The mail server sent an incorrect greeting:  Cannot connect to SMTP server 212.159.8.107 (212.159.8.107:25), NB connect error 10061."

The error is apparent on two different SMTP servers that I use, the other error message is:

"An error occurred sending mail: The mail server sent an incorrect greeting:  Cannot connect to SMTP server 212.159.9.108 (212.159.9.108:25), NB connect error 10061."

The error does not occur when I send emails via a Groupwise account.

When I turn off the AntiSpam, the connection is made and the email is sent OK.

I do have McAfee VirusScan Enterprise running (a requirement of one of my clients) but the problem only arose when I downloaded and installed the trial of avast Internet Security with the Anti-Spam module.  The email client was fine with McAfee and avast Free running. 

Hope this helps?  I can always keep AntiSpam off and rely on Thunderbird and ISP antispam functions.
Thanks

[DavidR]

Of course the problem would only occur after avast was installed as the conflict is only likely to happen when two elements clash. I don't know if McAfee also be monitoring email and or spam.

Having two resident anti-virus scanners installed is one too many and not recommended as rather than provide twice the protection it can cause conflicts that could leave you more vulnerable.

No doubt you are aware that resident AVs load low level drivers and it is these which are most at risk of conflict, so I honestly can see how you could fairly trial AIS whist having another resident AV installed.

I'm not familiar with the Groupwise account you mention, if this were webmail based then I don't think that the Mail Shield or anti-spam would be monitoring that activity (only standard email ports and email clients).

[Ragus]

Thanks - I appreciate the potential conflict between McAfee and avast - but unfortunately I cannot "officially" turn off McAfee but I will do so to test out avast further.  In any cvase I have been dis-satisfied with McAfee as it failed to alert or prevent three serious malware attacks which were the reason I turned to avast. Thanks for your help.

[DavidR]

You're welcome.

If you have space on your hard drive I guess you could set up a partition for a VM OS installation and keep McAfee on that.