The actual problem is that Pegasus Mail has to extract a temporary copy of the attachment from the message. That temporary copy filename is passed to Virscan and then the AV product to be scanned.  At some point the AV if running in realtime monitoring mode, detects the creation of this temporary file and calls the main AV engine to scan it. The startup of the AV engine may take some time. If it is found to be bad for any one of several  reasons, it will either delete or quarentine the file.

This then takes away the file for either Virscan or the AV file scan request. This may occur before/during/after the file has been opened by the application(s). It is this opening process, a system call that cannot handle a file being stolen away from its control.  That is why, preventing the AV from monitoring the new mail directory always is the solution.

Martin 

Yo people,

I've seen several messages recently on the support forums, where the solution was to deactivate the antivirus app for the Pmail folders.

I understand this is necessary sometimes for Pmail as it is now. However, for the future, I consider not being compatible with a very common antivirus app a major bug. Not only a bug, I suggest that a mail program which is not compatible with avg or avast or avira or such is downright an invalid mail program.

Imho this is a priority, way before calendar. A mail program for which you can't check viruses is just an alpha version, not even beta. An alpha version is when there are dangers for your system. That is obviously the case if you can't check mails.

And No, no no no, arranging things with tape and wire so that this folder does this and the other folder does that won't do. The mail is checked or it's not checked.

[quote user="arnaudherve"] <...> several messages <...> where the solution was to deactivate the antivirus app for the Pmail folders. <...> not being compatible with a very common antivirus app a major bug. [/quote]

This problem is rather common with other email programs too - e.g Outlook - because of technical reasons. For AV programs, a file is a file is a file. If it is found to contain a virus, it gets deleted, quarantined or "disinfected".

When the file happens to be the email database... well, too bad. Best case: You lose a message folder. Worst case: Your entire email history is lost. The root cause of failure is that the AV scanner meddles with files it really doesn't know enough about. Hence the non-perfect "white-list email folders" solution, which i sneeded for most email programs. Possibly with exception for the major ones, where the AV scanner may be aware of which file extensions to avoid dealing with - but that is essentially the same as whitelisting email folders.

(One alternative is for the email client to store messages in separate files, like Pegasus does in the New Mail folder. In this case individual messages might get lost/destroyed, but the rest would remain unaffected. However, this has indexing and performance implications which is likely the reason we don't see many programs using that storage format.)

My conclusion is that the problem lies more with the AV software than with Pegasus. Compatibility goes both ways in this case and I think it is a bit unfair to blame Pegasus.

[quote user="arnaudherve"] <...>The mail is checked or it's not checked.[/quote]

Messages can be scanned on arrival, to find out if they are likely to contain viruses or not - given the signature database used at that time. A new virus will go undetected until messages are re-scanned using an updated signature database. So, yes: An email may be checked or not. And, no: Being checked is not the final verdict on viral content.

Re-scanning emails, regardless of which folder they are stored in, is a good idea - it should just not be done by the AV threshing through the email database. The AV plug-in for Pegasus scans attachments that have not been scanned recently. I like this approach; unfortunately I've had stability problems with the plug-in.

Suggestion 1: I would like Pegasus to run the AV scanner against received messages, rather than having the scanner as a POP3 proxy. The reason is that the proxy method interferes with data stream encryption; you can have either AV scanning or an encrypted connection to the post office, but not both.

Suggestion 2:  Make the functionality of the AV plug-in an integral part of Pegasus. This would enable a nicer user interface, with better feedback during scanning and might avoid showing a console window.