Thunderbird can check for, and retreive, email regardless of whether I enable the rule that allows access for ashMaiSv.exe. Is ashMaiSv.exe only for outlook or outlook express? If so, I might as well forgo the rule. Thanks! P.S. Cross-posted to alt.comp.anti-virus.
The Internet Mail provider (ashMaiSv.exe) is totally unaware of any email client. It works by intercepting POP and SMTP emails calls that are absolutely identical in every email client ever written (they have to be - to connect to mail servers they must adhere rigidly to the very old and cast in concrete POP and SMTP protocols). This includes Thunderbird.
The Internet Mail provider only intercepts emails being received or sent through the standard email ports for unsecured emails (POP port 110 and SMTP port 25). If email accounts are set up to use secured connections they will use other ports that are not intercepted (and must not be) by avast. A typical example of secured email is GMail.
If you want secure connection emails scanned by avast then, at present, you need to use a free third party program called STunnel which will manage the secure connections to the mail servers and pass the emails to/from Thunderbird (completely and securely inside your system) in a way that avast can scan.
avast has reported that this functionality will be provided directly by avast in the next major release of avast.
Just one extra thought regarding Thunderbird. If you receive emails from a Webmail service such as Yahoo or Hotmail using YPops or the Thunderbird Webmail extensions then they will not, by default, be scanned by avast. If you do use these features then a small change in avast’s Internet Mail settings can ensure that such mail is scanned. If you need more information of this just let us know.
ashmaiSv.exe is an external generic scanner for email clients (as comprehensively explained by alanrf) for POP, SMTP and IMAP protocols. Exceptions are Outlook and The Bat, which have their own internal plug-ins.
Just a small note: avmaisv.exe (or Internet Mail Shield) would work for Outlook or The Bat in a similar way it works for other clients. Only that the internal plugins for these two mailers are more convenient and support more features - so to prevent double scanning, once the internal plugin is loaded, Internet Mail Shield is disabled for the hosting process.
Thank you alanrf, Vladimyr, and lukor. I’ll leave it as-is for the time being. I only use thunderbird (and webmail interface sometimes, but I assume that Web Shield takes care of the latter).
If you are using the Thunderbird Webmail extensions for Hotmail then avast Webshield does not scan the mail (it does not understand the Microsoft proprietary connection - same is true for Hotmail with Outlook/Outlook Express/Windows Live Mail).
If, by Webmail, you mean using a browser to access Webmail then the Webshield is scanning the browser connection.