Checking emails takes ages - only via WLAN, mind you
Good day together
Retrieving my Swisscom emails via Thundebird, Outlook etc. takes ages. What’s strange is that this is only a problem in my home WLAN. But if I switch to the mobile network, i.e. WLAN off, then it works normally. This applies to iPad and iPhone. There is no problem on the desktop.
Does anyone know the problem, or more precisely, what could be the cause? I am using an Internet Box 4.
Thank you and best regards.