Fixing the Error 'Uncaught Exception: Expected response code 250 but got code "235", with message 235 2.7.0 Authentication successful' When Sending Replies to Tickets

Overview

When trying to respond to a ticket in Kayako Classic, users might see the following error while using Office 365 as SMTP:

Uncaught Exception
Expected response code 250 but got code "235", 
with message "235 2.7.0 Authentication successful" (235) in 
./__swift/thirdparty/SwiftMailer/classes/SwiftMailer/Transport/AbstractSmtpTransport.php:383

This was a bug in version 4.93.07 and the issue was fixed in the  SWIFTMailer library of Kayako Classic version 4.93.10.

Information

The default SMTP timeout value in the SWIFTMailer library was too low (set at 30 seconds only) on version 4.93.07 which causes the issue when executed on slow-network SMTP servers. The fix deployed on Kayako Classic version 4.93.10 was an increase in the SMTP timeout value to three (3) minutes, which will prevent timeouts in slow-network SMTP servers.

If you are experiencing this issue and you are using a version that is older than Kayako Classic 4.93.10, you need to upgrade to the latest version.

• For Kayako Classic (Download), to upgrade your instance, please visit the Upgrading or Downgrading Your Kayako Classic Download article for guidance.

Note: To check the version of your Kayako Classic installation, please see the instructions provided in the KB article Identifying a Kayako Classic Version.