Smtp Error Message

Any idea why I am getting this error message?

Note after my migration today all is well except I don't get admin emails after an order but I do get Stripe receipts emailed after an order is made.

Also when I check teh send email box to admin and make a "save" no email is ent as is normal.

Very puzzling...

ErrorMessage could not be sent.
Mailer Error: SMTP connect() failed.

I just saw this thread which while not exactly the same is similar:

I checked my email page and all information is the same as before my migration and I use GMail for my mail.

It seems like Gmail senses my new server as being different and is not happy...

How to fix this?

ensured 465 port is whitelisted now in every csf option in my Firewall and all seems to be OK now.