since 4.5, when sending emails with attached files with the most recent Pegasus Mail 4.21c, the progress indicator of the sending process in Pegasus no longer works if scanning of outgoing emails is enabled in avast. This has the unpleasant side effect that Pegasus thinks that it does not send anything and issues a timeout warning after 30 seconds and stops the sending process. So, basically, sending of mails with larger files attached does not work anymore in Pegasus, if one scans outgoing mails.
It sure is a solution. It only means that you tell Pegasus to have a little more patience, that’s all. Nothing will be changed in the way the system is working.
In earlier avast versions mail were routed through the localhost (127.0.0.1) and this would pass through very quickly and/or possibly form a buffer that masked any timeout settings.