To sum up, the problem is not with the ipad or the email provider, but with the ISP and its security measures.Įdit: forgot to mention that i also had no problem sending emails at home with my laptop over wifi, but that was because i was using webmail, which uses the normal http port (80 i think) which is not blocked. Mac’s Mail client, however, seems to have its own ways. Which explains why Outlook worked even when Via headers were present. I'm pretty sure this is the solution people are looking for, though the specifics will depend on your ISP. Outlook for Mac handles these responses as expected, including authentication information when Persistent-Auth is set to false by Exchange server. I've seen a ton of discussions online about this problem, with almost none of them providing any solutions. This issue occurs if either of the following conditions is true: The version of Exchange Server that youre running uses TLS 1.1 or 1.0. Also, mailbox synchronization might stop unexpectedly if your Exchange account is already added to Outlook. I also had to enter my userid and password (i had forgotten i even had these). The connection to your mail server timed out. All the incoming settings stay the same, but I changed the outgoing smtp server to on port 587 (25 is always blocked).

They (and most major ISPs it seems) have all these security features to prevent their wifi networks from being misused, but they allow their customers to use the optimum smtp server to send emails using other accounts.

It turns out the problem was not with the email provider, but with our ISP (optimum online). My ipad could receive emails but not send them- only at home, though, not at work. I had a very similar problem and was finally able to solve it after a huge amount of aggravation.

Connect outlook to mac mail server