Freshservice custom mailbox error - Mailbox limit exceeded

Copper Contributor

Getting below error email frequently from FreshService (An application which is using one of our mailbox from outside with SMTP authentication). That mailbox is operating on our on-prem exchange 2016 in Hybrid mode, what exactly should we check in exchange logs for this custom mailbox as that is working fine and we are receiving emails. Message rate is already unlimited on that receive connector, I don't know what logs should be checked as email from vendor about limit exceeds is coming frequently and description is very generic. 



Dear Admin,

Your Freshservice custom mailbox xyz support(email address removed for privacy reasons) is unable to send outgoing emails due to 'Mailbox limit exceeded'.

What are my next steps?

  • If you had sent huge volumes of emails in the last few hours, you might have reached the upper limit set by your mail service provider. Contact your mailbox provider to increase the limit or try again later.

Can Freshservice help me with this?

  • Freshservice cannot help with this issue because this is a custom mailbox. We can only read and relay error messages from your mail provider.

What happens to all the tickets/emails that should be outgoing via this mailbox?

  • We will queue your emails for up to 72 hours and try to send them once your mailbox reconnects. Success isn't assured though due to various factors.
  • As a best practice, it's advisable to re-authenticate your mailbox within 72 hours after disconnection.
2 Replies
Message limits can be set at various points in the message routing. How does mail flow from the 3rd party to the intended recipients? Look at all the devices that are in that message route and make sure that the mailbox is not exceeding any limits
so the application is reaching to this mailbox (on-prem) via receive connector with SMTP authentication where the limit is already set to unlimited once SMTP authentication is successfull. Then the intended recipients are on M365. There's no any rule for email routing we have configured.