Thank you Vince. I will answer your questions, etc, but first, I see you are providing a different SMTP setting than I was provided previously and using for years now. Actually, I was instructed to change to this SMTP setting from the one you are giving me. Hotmail/Outlook/Microsoft supposedly had changed what was to be used, decided all should go through office365. It harked worked fine for years now, fixed the problem of using live.com. This current issue seems to have started only in recent time, recent months. Do you know if Hotmail/Outlook/Microsoft has changed it back?
I am using: smtp.office365.com
You are saying to use: smtp.live.com
I will try that. But it will take some time before I can get word back from people to whom I send, so I won't have immediate results.
To your questions:
“•Can I know what is this desktop email client app that you are using?”: I am not doing this from the desktop, I am doing it from Gmail online.” I am using them as if they were a desktop client.
“•Is this also happening when sending/receiving emails in the Gmail.com webmail?” and “•Is this happening to all devices, browsers, and networks?” Yes, that is where it is happening, I do not use and desktop client. The people receiving the e-mail tell me later the e-mails are going to their Junk folder, or other times I get a message back that it was rejected. I can’t tell if that rejection is coming from Hotmail, or from the receiver’s e-mail. But it works fine if I instead send it direct from Hotmail. The people I am sending to normally get their e-mail on mobile, and they tell me there are no settings there (mobile) to protect e-mail from my address nor to make a rule to never send it to Junk. Coincidentally, two who have told me this are using Hotmail on mobile. So it can’t be fixed on their end. I am sending from Gmail, via SMTP through my Hotmail address from my computer, not mobile.
To clarify your first paragraph, I’m not talking of sending e-mail from my Gmail account to my Hotmail account. I am sending an e-mail to other people, from g-mail using the SMTP settings to send it through Hotmail so they get it from my Hotmail address. (I've been doing it that way for decades, originally just because Hotmail was slower.)