Account blocked for IMAP use

Account blocked for IMAP use

Hello,

My email client (Evolution) can't sync mail anymore. It gives the error:
"Your account is temporarily blocked for IMAP use. This may happen if you exceed the maximum number of simultaneous IMAP connections allowed. Kindly try again after some time."

This is my desktop client. On my phone K-9 Mail still works well.
The error exists at least since yesterday morning. Yesterday there was a time in the evening when it worked again but now it's broken again.

Please advice.

Tobias