Avast Home 4.6.691: hMailServer: Transparent IMAP - blocks real provider

[sumnerp]

I've suddenly started having problems with IMAP and avast. I'm using hMailServer and following a reboot I can not access mail using IMAP if the on-access transparent mail scanner is running in Avast. If I stop the on-access scanner I can access hMailServer, but once I start the avast service it picks up attempts to sign into hMailServer's IMAP ports and tells me there there is no IMAP service running.

POP3 and SMTP transparent proxies are working fine (but are handled by Mailtraq rather than hMailServer). HMailServer has been running fine behind the transparent proxy for several weeks. I'm not sure what triggered this change in behavior, a reboot or an avast update.

Grateful for any thoughts or advice. I've currently turned off the on-access scanner for IMAP, not unduly worried as by this stage the incoming mail has already been scanned but I'd like to know what is going on.

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Peter Sumner

[vojtech]

Isn't a firewall blocking the connection ? Mail client must be allowed to connect to the mail scanner (address: localhost, port 12143 by default) and the mail scanner (process ashMaiSv.exe) must be allowed to connect to your mail server.

[sumnerp]

Vojtech - thanks for the reply. No it was not a firewall issue, mail clients could connect to hmailserver on port 143 if Avast was not monitoring the port. Start Avast and avast picked up the session and compained that a real IMAP server had not been set up (as if it were explicitly proxying the port rather than doing the transparent redirect.

Anyway, the good news is that it has all started working again. I know I've not updated hmailserver and Avast shows only updates to VPS not to the program. Could a VPS update have caused this?

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Peter Sumner

[vojtech]

I don't think that a VPS update could cause this.
Did you restart computer to make it work again ?

[sumnerp]

Vojtech - thanks again for the response.

I noticed the problem after a reboot, but when I had the fault I checked that it did not clear after a second restart. I also checked that stopping the avast internet mail scanner did allow me to connect to hmailsever, and that when a restarted the scanner it re-blocked by connection to the mail server. I also tried stopping and starting hmailserver but this made no difference. After running these tests I turned off IMAP scanning and restarted the internet mail scanner, this ensured all my mail was scanned and allowed me to connect.

When I saw your response I wondered if it was an hmailserver issue. So I closed it down, ran up Hamster and found that I could connect to its IMAP server with the avast scanner running. Thinking this indicated indeed an hmailserver problem I shut down Hamster, restarted hmailserver and was surprised to find the problem had gone away.

I agree,  I can't see how a VPS update could cause this, yet it seems to be the only thing that changed.

As I can't reproduce the problem we can blame it on user error - though I'm pretty sure of my facts. I'll post again if it recurs.

Thanks for the advice. I'm an extremely happy avast user.

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Peter Sumner