Probs best emailing support with as debug file......
(send the log to support at firetrust dot com)
As yes, there could be any number of reasons for this, first, click Settings>>Email Accounts, click the problem account and check your POP3/IMAP server and username is correct, and re-type your password.
Click OK to save any changes.
If this does not help, could you please create and send a debug file showing this problem.
To do this..... (please start with MWPro closed)
1.) Open Mailwasher Pro (if using Windows vista or above, start it by right clicking on its shortcut and clicking, "Run as Administrator",) then click, Help>>About
2.) Ensure that the, "Enable extended error logging to Data directory" checkbox is ticked and click, OK.
3.) Use MWP till you get the problem.
4.) When this is complete, (or you get an error)
5.) Click, Help>>About, and click the blue link below, "Enable extended error logging to Data directory" to where your Debug file is created.
6.) Minimize the Application Data folder, and click OK in the Help>>About Screen.
7.) Click File>>Exit to close Mailwasher Pro.
8.) Maximize the Application Data folder, open the file, "MailWasherPro_debug.txt" (it may not have the .txt on the end)
9.) Click, File>>Save As,
10.) Save the file to a location where you can find it later.
11.) Email logs as attachment to support.
(NOTE: if you get a message from Windows or the windows registry asking for permission, click YES as this is when the account settings etc are saved to the debug file)