Server not accessable - although acessable with other clients

Hi there,

Problem: mail actualize provoke red warn triangle. triangle shows up after over and over click and connection check.

Macos 10.15.7, EmClient 8.0.3499 (72a5416), licensed

Error message: connection failed due to temporarily unavailability of the server (not true, checked on other systems and clients, working perfectly) or wrong account entries (not true, send and receive worked half an hour before with same entries as used for other clients).

Ordered yet a ticket for this issue, but as other tickets days before still waiting on feedback.

Any comments?