Are they sent to junk/spam by the recipients' filters in their mail clients, or by the filtering applied by their mail providers, before the messages are accessed by mail clients? if it's the latter, whitelisting or unblocking, or adding to contacts, must be done through the webmail access of those accounts. In the meantime, you can avoid being marked as junk by sending plain text messages without remote images, a signature, or messages that are mainly links..

Dunno!

I do know that they have marked as not junk and suddenly in an email chain one will randomly go to junk despite numerous times of them telling the system not junk.

My work means that I needs to use links and a signature which is rather frustrating!!

Thanks

If they have marked messages as 'not junk' in their mail apps, it will have no effect if the filtering is done at the mail provider end. Some users might be unfamiliar with viewing their account in webmail, but that is often the only way to whitelist senders. Once that is done, messages with links, images and signatures should go through unblocked.

How do you do that? (Thank you!)

Log onto the account with a web browser, then look at messages that have been moved to the Spam/Bulk/Junk folder and use the relevant options to unblock the sender. Often it is just a matter of adding the sender to the webmail address book.

Thank you