Stuck in the Mud emails

Seems my mails and replies want to take a short break before sending. Never behaved like that before. All else is fine on incoming. Also can’t get quick response bringing up links, some coming ten minutes later. Outside of Client I have no trouble with speed. All incoming seems to be acceptable as well as my response to sites.
One other item: my emClient screen wants to shrink font size and somewhat overprint lines. Goes into that mode whenever it wants to but quick sessions don’t trigger it- only when I have spent some time with emails. ???

sorry for the delayed reply - could you please tell me what mail provider do you use? What is the size of email being sent? Does the problem still persist?
As regards the second problem: could you post here a screenshot please? Than kyou.