I downloaded MailWasher Free in order to test it on an email account I run on a different email client (Mailbird). After the test, I un-installed it. When I opened EM Client later, one of my two Inboxes was cleared, except for the mails of the last 2 weeks. The other Inbox was not affected, neither those on Mailbird. MailWasher told me: “When you first install Mailwasher (Pro or Free) it asks if you want to setup your email client to NOT leave a copy of the mail on the server (IF enabled), and if you select yes, it disables that function, then when your email client restarts, any old emails it has already downloaded are removed from the mail server.” It looks like MailWasher configures EM Client, even though it was meant for another email client (Mailbird). Please back up all your mails on EM Client before you install MailWasher, or move your Inbox to a sub-folder on your computer.
The access of third-party applications to EM Client should be subject to an express authorisation, maybe something for the next update.
That is a common setting for POP3 accounts to delete email from the server after it has been downloaded. The emails will still remain in your Inbox within the mail client.
My understanding was that MailWasher connects directly to your email server, where it does what it does with email in the Inbox. That is totally independent of any email client. That means you do not even have to have a mail client installed on the computer for MailWasher to function. Later, when the mail client accesses the server it gets the cleaned Inbox.
As far as I know third party applications cannot access eM Client’s settings. I will run a test on MailWasher later today and post the results here.
Decided to test it now before I got busy.
I installed MailWasher, and got the following screen in the setup.
I left these options as default, and MailWasher did not make any changes to eM Client’s POP3 or IMAP settings. Instead, I think this notification is asking you to do it manually because it is not able to do that itself.
What I did discover is that MailWasher was using the account settings from the previous screen in the setup, then logged into the mail accounts on the server and made it’s changes. That has nothing to do with eM Client except that it is the same login credentials. It would do that regardless of the email client, and will do the same even if there is no email client installed.
I would suggest that the problem exists between MailWasher and your email server. MaiWasher did not alter eM Client’s settings or emails in any way. If the emails were no longer visible in eM Client that would be because the account is setup as IMAP and that eM Client is merely reflecting what is on the server.
Thanks for looking into this. I really like EM Client and am a very satisfied user (just in case there are any doubts). The MailWasher was run on Mailbird, to test it on an unrelated email account. MailWasher never had the login credentials for my work emails which I run under EM Client. I would never attempt to apply a 3rd party software there, without asking my IT department for their opinion. For some mysterious reasons, my emails stored on the server for one of my two work emails I run under EM Client vanished. MailWasher also do not have an explanation, other than “it’s weird”.
I just want to advise users to back-up their data, or move their important mail to a subfolder stored on the computer rather than the server, before trying MailWasher or any other similar application.
Right you are Simon. Always good advice to backup anyway, but especially before you try something new.
MailWasher works by detecting and deleting email from the server before your email client can access them, so it has to have the credentials for your email server, otherwise it cannot work. Somebody please correct me if I am wrong. So I think if MailWasher did not have that account’s details, then it is not at fault for deleting those emails. 
Did you maybe have Automatic Archiving enabled in eM Client? That could have moved the older emails to another folder. Or maybe another device is connected to that account, and could have done the same thing.
And of course we can’t suspect your company server of doing anything stupid like deleting or moving them, because it doesn’t do things like that, does it?
Hi Gary. My company server would not do that, as I now have no work emails received before 6 Feb. Luckily I usually acknowledge clients’ mails, so I can look in the “Sent” folder for some clues. I just started working with eM Client last month, so no auto-archiving yet performed. It’s a lesson learned.
There have been a couple of incidents where emails older than a specific date have disappeared for no apparent reason, later to be reported as a problem with the server.
Maybe you could ask your server admin to do a restore of your account. Just export what you have before that happens in case the backup is a few days old.