Why does Avast Internet Mail scanner put a limit on the size of emails I can send ?
It does not.
Do emails sent and received by Gmail get scanned by Avast Internet Mail scanner
No, they do not.
To expand ...
I just sent an email with an attachment of 8.2Mb through my ISP email account to a Hotmail address. The mail was scanned by avast being sent and it was scanned by avast being received. Both functions completed without any problem.
I am using avast 4.8 beta. My mail client is Thunderbird. Before anyone says this a not comparable let me make clear that avast
does not have the faintest clue which SMTP client you use to send email. Every POP/SMTP mail client in existence
has to obey the very old, very clear and very standard rules of POP/SMTP and it is simply the standard connections for POP and SMTP that are intercepted and taken over by avast irrespective of mail client.
So why is there a problem? Well, obeying the rules of POP and SMTP is about the only standard that mail clients follow, every other aspect of the way they work is individual to each product. In particular, mail clients can be set to expect to get regular feedback on the transmission of email messages to the SMTP server. If they do not "hear back" from the server at regular intervals they typically give a timeout error. The avast team has gone to considerable effort in the past couple of years to take care of the issue of providing these contacts back to mail clients to avoid the problems that were often seen in the sending of large email attachments.
I will admit that I far from being a fan of Incredimail, my experiences of it have largely been confined to helping others with issues encountered from having that product on the their systems. I have not investigated in depth the issues that can be encountered in Incredimail with the sending of large attachments scanned by avast. Terminating the avast Internet Mail scanner means that direct communication between Incredimail and the SMTP server is restored and whatever it is in Incredimail that is "unhappy" with in the avast intercept ceases. Taking that action also means that your inbound mail is not being scanned.
However, as a general point I have to say that the scanning of outbound mails is largely useless and a waste of time. Nobody in their right mind should trust anyone else's scan of their mail and should ensure that they scan their incoming mails or at least be sure that it has been scanned by their email service. If you are using avast to protect your system along with a good firewall then the chances of the outbound scanning of your email finding a problem is very close to zero.
So, if you are experiencing issues with the outbound scanning of your mail then just turn off the outbound scanning of your mail in the SMTP tab of Internet Mail scanner. That way your incoming mail will still be scanned and you can avoid the problems caused in the rather unnecessary outbound scan.
For GMail ...
GMail insists that your POP and SMTP connections are secured connections to the server. This is much like the secure connections your browser sets up when you connect to your bank online. Nobody, and no antivirus program can scan these secure connections (that's the point of them being secure). GMail says that it does scan attachments of your emails for you but it is not entirely clear if they provide full message scanning.
There is a way to get these mails scanned by avast but it requires that you install a free third party product (called STunnel) that will manage - inside your computer - the secure connections to the mail servers and then pass the messages - again entirely and safely inside your system - from STunnel to your mail client of choice so that they can be scanned by avast. It can appear a bit daunting at first glance to set up but others have reported how to do it here in the forum and if you care to learn more then please use the forum search function for "STunnel".
If you can be patient then the avast team have said the the equivalent functionality of STunnel will be built into release 5 of avast that is expected to be available later in 2008 - so there will be a way of managing increasingly prevalent secure email connections and still having avast scan the mails without the need for the third party program.
