Yes, very likely your ISP has stopped support for the older SSL method MWPro 5/6 uses, only our later MWPro 7.xx version has been updated to the new SSL method....
To test this, install either MWPro trial version from here:
http://www.firetrust.com/products/mailw ... o/download
OR the free version from here:
https://www.mailwasher.net/download-mailwasher-free
(Note) that this wont effect your 5 or 6.xx version at all)
OR, below is another option to try out first if you wish.....
We have recently found that sometimes you can get the new SSL working by extracting and placing the attached files in the install folder, replacing the old.
This folder is usually:
C:\Program Files (x86)\Firetrust\MailWasher Pro
It will generate a failure to load SSL libraries on startup, but setting MW to Suppress All Errors will hide that:
Tools>>Show Errors Digest, tick, "suppress all errors">>OK.
It might also require MW to be set to sequential checking also.
Settings>>Connection Options, select, "sequential checking">>OK