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Consumer Products => Avast Free Antivirus / Premium Security (legacy Pro Antivirus, Internet Security, Premier) => Topic started by: sjoukew on August 04, 2008, 08:11:02 PM

Title: Thunderbird mail error after installing Avast
Post by: sjoukew on August 04, 2008, 08:11:02 PM
I am using thunderbird as email client, and it worked fine.
After I installed avast antivirus I am getting the error message:

Sending of message failed.
An error occurred sending email: Unable to connect to SMTP server mail.initfour.nl via STARTTLS since it doen't offer STARTTLS in EHLO response. Please verify that your Mail/News account settings are correct and try again.

I double checked the settings, and they are correct. I also tried the mailserver on another pc without Avast, and it did work correctly.

What do I have to do to send email and use Avast antivirus?
Title: Re: Thunderbird mail error after installing Avast
Post by: DavidR on August 04, 2008, 08:51:57 PM
Is your ISP using SSL (secure encrypted) email, the error tends to suggest that is the case ?

avast is unable to scan SSL/TLS email because it is encrypted, avast also can't handle the STARTTLS that is causing the problem.

The problem is more likely that your ISP is using port 25 for secure encrypted traffic when this is the standard port for regular unencrypted SMTP traffic or you have added the secure port to avasts redirect ports.

What port are you using for your SSL/TSL email ?

avast's email scanner is monitoring ports 25, 110, 119 and 143 SMTP, POP3, NEWS AND IMAPI protocols is expecting only these protocols through the respective port, so using one of these standard ports for non-standard purposes is what is causing the problem.
Title: Re: Thunderbird mail error after installing Avast
Post by: sjoukew on August 04, 2008, 09:16:28 PM
My provider uses TLS or SSL, and unencrypted is not supported.
I am using default port, port 25 TLS or 465 for SSL.
Title: Re: Thunderbird mail error after installing Avast
Post by: Lisandro on August 04, 2008, 09:40:15 PM
avast does not support encrypted connections TLS and SSL...
I'm not sure if Stunnel does the job (http://forum.avast.com/index.php?topic=10428.0).
Which is your operational system? Do you use any antispam tool?
Title: Re: Thunderbird mail error after installing Avast
Post by: DavidR on August 04, 2008, 10:20:14 PM
Well that is the root of your problem using port 25 for secure email. This will fail (with the message you are getting) as avast will be expecting the standard SMTP protocol through that port.

Even using STunnel as suggested by Tech I don't think will work as you are using port 25 and avast redirects on that port. STunnel would intercept on the other secure ports, examples below, allowing avast to scan that email.

I assume your POP3 (receipts) use a different port to the standard 110, as you make no mention of not being able to receive email ?

You could check with your ISP if you can use port 587 for TLS secure SMTP email. This won't scan your outbound email but would resolve the problem of the email not being sent as avast wouldn't be intercepting the port 587 traffic. Then STunnel could be used and allow avast to scan your secure email traffic.

Example secure email ports.
SSL/TLS (Secure) Ports
POP3 995;
SMTP Ports, Thunderbird-587 - Outlook/Express-465.
Title: Re: Thunderbird mail error after installing Avast
Post by: Lisandro on August 04, 2008, 10:24:30 PM
What I'm not sure is if Stunnel allows TLS connection...
I use it only for SSL.
Title: Re: Thunderbird mail error after installing Avast
Post by: alanrf on August 04, 2008, 10:43:56 PM
As noted above - avast does not work with using a secured SMTP connection on prot 25, very few mail servers use this combination.

To retain that configuration and avoid the problem with avast:

Internet Mail Provider > Customize > Redirect tab > enter the address of your SMTP server  in the "Ignored addresses" box > OK
Title: Re: Thunderbird mail error after installing Avast
Post by: sjoukew on August 07, 2008, 12:19:02 PM
Thanks for the info, now I at least know what the root of the problem is and how to solve it in my case.
I don't need the smtp virus scan, I know my provider scans it and will warn me if I have a problem. I haven't had a virus in at least 10 years, so I am not that worried.
As long as all the incoming information is scanned I should be save.
Title: Re: Thunderbird mail error after installing Avast
Post by: DavidR on August 07, 2008, 03:08:52 PM
You're welcome.

The outbound scan is helpful in other ways, e.g. with the sensitivity set to High, it could be the first indication that your system is sending out spam with an undetected or hidden spambot.

So I would suggest you check the ISP and ask if there is another port you can use for secure SMTP, that way avast can ignore your secure email (or allow you to use STunnel) yet provide protection against unauthorised email using the standard smtp port 25.