E-mail problems

[B.S.F.]

When I click on "Get Messages" this message appears on the screen. ( 3-digit number blanked by me) It appears that I can't receive any e-mail until this has been dealt with.
Could someone tell me what it means, what to do, what not to do, what to click on etc. All in simple language please without any jargon,
abbreviations, computer slang if possible. Thank you.
.W

[B.S.F.]

The notice has disappeared and everything appears to be back to normal. Could it have been part of a scam ?
.W.

[speleomike]

That error suggests to me that dodo didn't renew their SSL cert and they were serving an out-of-date cert or a self signed one at that time. Now they have fixed it. Nothing wrong at you end.

[B.S.F.]

Thank you for your clear answer.
.W.