Hello Alex T⚜️
I confirm that the exclamation symbols do not appear.

As for the SMTP service, I use Mailjet for one web page and for another web page I use the one provided by TMD Hosting through the VPS hosting that I have contracted.

LeonidS asked me for access data to cPanel, UNA Studio, etc. I just sent them to him. I suppose he will want to see this that you indicate.
Thanks.