I may be busy with some other application, could be whilst browsing on Internet, could be when creating an email, could be whilst using Explorer (or, in my case, Directory Opus), whatever.
Then suddenly Mailwasher pops up and I have to minimize it again.
It doesn't do anything, it just pops up.
Mailwasher is just in the taskbar, in the background, I don't activate it.
FWIW - my settings are as follows
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p.s. it would be nice if an image could be inserted as a thumbnail, expanding to 100% when being clicked on, similarly to imgur (url link)