Keep in mind that if active scanning is enabled on the %temp% directory then attachments get scanned when they are written as temporary files at the time they are opened.  Virscan simply adds an extra level of protection.  It is most valuable when used with the command line scanner of a different AV product. 

Virscan was extremely valuable back in the days when on demand scanning was the only option but the current capability of active scanning can make Virscan unnecessary.  It remains a valuable protection option for anyone who feels the need though.

In short, active scanning is must.  Otherwise Virscan is a must.

As previously stated, Pegasus Mail directories should be excluded from active scanning because it can adversely affect performance and because file damage is a concern when Pegasus Mail and the AV scanner compete for access to files.

Pegasus mail v4.70 on Win 7 64 bit, though problem was occurring on earlier versions too.

Have looked through forum but no symptoms quite like this. Program is unresponsive (can't type, scroll, anything) while sending (SMPTP) and receiving (POP3), but recovers once sent. Sometimes takes a little longer, screen greys out, circle cursor spins, and then recovers.

Things to try? Wondering if Norton Internet Security 2015 could be a factor.

This is an oft reported problem with v4.70 and previous versions. (As you note)

AV programs have the capacity to interfere with server connections. Have you tried temporarily disabling Norton to see if it is a factor?

At the very least, disable any email scanning by Norton and insure that the \Pmail directory and all subdirectories are excluded from active scanning.  If the mailboxes are located somewhere other than \Pmail\Mail then exclude the entire \Mail directory as well.

Caisson is correct about the experience by many folks (including me) with the pauses during SMTP and POP3 activity on v4.70.  It is worse on some machines than on others and the specific cause has not yet been identified.  Best just to take a breath and let Pegasus Mail finish the activity that is occupying it.  "Not responding" displays are system generated when Pegasus Mail is too busy to reply back to the OS to say "I'm still here" so should be ignored unless they last for several minutes.

I agree with Caisson & Brian F.  

And here lately it seems to be getting worse, quite likely because of factors beyond the direct control of either PMail or the OS.  W7, W8, W10, all have issues.  

I suspect that it's a combination of:

- latency in client - mail server / client - web page communication channel, especially when there's a wireless / microwave downlink involved;  

- the inundation of web bug / beacon "salted" .gifs / pixels in HTML email, which cause the client to be deposed by the server, while it waits . . . and waits . . . and waits;

- concurrent open application extravaganza on the client machine, which may stress the graphic display system screen refreshes;

- and so on.  

Which reminds me: not too terribly long ago there was a thread on this forum about phony "Bad password" returns from the mail server POP3 connection.  This in my experience can be occasioned by communication channel latency problems, again more chronic if a wireless link is having a suboptimal day.  The server responds, receives no client-side ACK response within the time frame of its expectations, so coughs up a Bad Password error.  

I'm with Brian on the "Best just to take a breath" approach.  In the old days I could have said, "just light up a smoke", but that's considered bad form these days.  On the other hand, Caisson's "temporarily disabling Norton" approach is healthy enough, given that in my experience of it Norton interferes with just about everything, including lighting up.  

- Christopher Muñoz-Keatts

Thanks for all the replies so far, looks like finger pointing squarely at Norton. I have tested by turning off AntiSpam in Norton Internet Security and the symptoms go away immediately, ie. can now scroll/click/type etc while sending/receiving emails. I will keep testing for a while to be sure, as sending/receiving is now very much quicker (1-2 seconds versus 10-20 seconds) giving less opportunity for the symptoms to show up.

As others have said, the problem has been around for a while, and sometimes seems worse (more time spent in the "hang" state, presumably Norton taking longer to do it's thing). Patience works wonders, but traditionally I have had check for new POP3 mail set to 30s which has really highlighted the problem ~ e.g. as much as two thirds of the time Pegasus being unresponsive. I can extend the check time, and can select the "idle" option so it won't check while I'm typing or moving the mouse, though the later seems only to work while focus is on Pegasus.

I might send off an email to Norton tech support, see if they can offer any insight. Will update here if I learn anything. 

You should adopt Brian's suggestion of permanently excluding your mail folders from virus scanning.

Martin Ireland's Virscan extension is useful for scanning mail attachments and is available via the downloads section of this site.