Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

In this Discussion

osTicket v1.10 (stable) and Maintenance Release v1.9.15 are now available! Go get it now

SMTP not working on office 365 premium account

Hi All,

I have migrated our mail to office 365 premium, and now I have problems with sending mails through osticket. Receiving mails works, but sending not. it gives the following error:

Sending Email via SMTP     
authentication failure [SMTP: Invalid response code received from server (code: 535, response: 5.7.3 Authentication unsuccessful [])]

There are a number of forum threads on this topic, but so far nothing has worked. The specific error I can't find either on this forum. Can someone help me?
My settings are as follows:


Logging in on IMAP works, sending mail doesn't work
osticket version: v1.10
PHP version: 5.5.26 
> openssl s_client -crlf -connect -starttls smtp -> connects with ssl from my server


  • put SSL:// in front of hostname, I don't recall if you need to do it for both of them, but the first one for sure if using SSL. Try it and let us know. 
  • Hi Synt4xError,

    Fetching the mails works fine. Sending mails does not work. With your proposal I get the following error:

    Hostname: ssl:// 

    Sending Email via SMTP     
    Failed to connect to ssl:// [SMTP: Failed to connect socket: stream_socket_client(): unable to connect to ssl:// (Unknown error) (code: -1, response: )]

    It looks like now it can't even connect anymore.
  • Okay so your only issue is with sending mail? 
  • This isn't response to your latest post, but please update PHP to 5.6.x, your version is not suitable for any edition lower than 1.10 for OSTicket. 
  • I migrated the mailbox away from microsoft to zoho in the end. I will update php 5.6
Sign In or Register to comment.