The following From Address form is becoming increasingly popular:
John Smith; on behalf of; John Smith, firstname.lastname@example.org
This can happen if you’re using Outlook and you substitute a From Address other than your own. If you want to know how to do this, then look it up. I’m not going to show you, and here’s [one reason] why.
In Outlook, if your recipients are using the Safe Lists Only Junk E-mail setting, this form of From Address is impossible to white-list.
The result is that each and every email you send to many Outlook users will land in the Junk E-Mail folder. If that’s where you want your emails to land, then fine. If not, then please change your From Address style to something that does not include the “on behalf of” nonsense.
Normally, one can right click something that’s in the Junk E-mail folder and choose the Never Block Sender option:
You can “Not Junk” this email, but you’ll have to do it every time, because you cannot white-list this kind of From Address. When this form of From Address is used, the Never Block options do not work, and all yield:
In fact, if the user has the “Permanently delete suspected junk e-mail” option enabled, they will never even see the email you send them at all. So, if you’re using the “on behalf of” style of From Address, and some Outlook users aren’t getting your emails, now you know why.