Common issues with email deliverability

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  • Elizabeth Toy

    How many attempts will Zendesk make to deliver an email before it quits trying?

    Just wondering because we CC'ed an email but it was spelled incorrectly when it was added, so we are receiving multiple "Undelivered Mail Returned to Sender" emails. I've corrected the email address, but that doesn't seem to have updated the already-queued-up outbound email intended to go to the CC'ed (incorrect/original) email address. Hoping they'll eventually stop. :)

  • Sean Cusick

    Hi Elizabeth,

    We're sorry that you're experiencing this. When a relay server does not respond with a permanent non-delivery smtp code then we will continue to attempt to send the email for five days before our deferred outbound servers finally give up. This is a relatively common time period to keep trying (when a definitive non-delivery response is not received) so that it excludes temporary server performance / outage issues. You can safely ignore these suspensions or bulk delete them as you see fit.

  • Teekodii


    There is an issue with this particular email, it is a gmail account and i don't receive her email at all and she also doesn't receive notifications when i send her email via Zendesk. i have checked suspended tickets to see if it was marked as spam but it isn't there. Kindly advise. Thanks  

  • Sean Cusick

    Hi Teekodii,

    I'm very sorry, but it is not possible to troubleshoot email based on description alone.Though, if her emails are not creating or updating tickets, and they are not arriving in the suspended queue, then it sounds as if there is something wrong with those emails. They are either not being sent/forwarded to us, or they are being hard-rejected once they arrive. If you are on the Team/Regular plan or up, then please open a ticket at

  • Lisa Rönnqvist

    Hi Zendesk support! 
    We are having trouble sending new tickets from our Zendesk to new recipients. The emails/tickets doesn't come through to the recipient. And we don't get at "did not send" e-mail back or any notification what so ever. Sometimes the email gets through and sometimes not. It does not depend om recipients emailclient as we have researched. We do not spell the emailadresses wrong. 
    What can we do to make sure that all new tickets/emails get through? 

  • Sean Cusick

    Hi Lisa, For us to investigate further we would need you to open a ticket with us at and provide recent ticket # examples and which updates you believe were not delivered. It also helps us if you enable account assumption as part of that process (Settings>>Security>>Global>>Allow account assumption) so that we can investigate. 

  • DeskPerk

    Hi All,

    Zendesk - Read Receipts, Public Portal for viewing / editing / solving tickets and Email Delivery Validation

    We are currently in the process of developing a new app / add-on service for Zendesk, to add some much needed features.  We are currently looking for people to help us test these features before we launch. Here is what we are working on:

    • Read Receipts (triggers and automations)

    • Public Portal for viewing / updating / solving tickets without needing to login

    • Email address verification (Coming soon) - Know if the email address is valid

    If you are interested in helping us beta test this new service, head over to and fill out the application.  We will be offering all these services for FREE during the testing period (At least through March) for anyone who signs up before January 15th and all we ask is for you to provide us with some feedback.

    If you have any questions, we will be happy to answer any of your questions.  Just head over to

  • David Andrews

    My Read Receipts for Zendesk already offers a proven read receipt solution. We currently process over 5 million pixels per day with single digit (in seconds) response times without fail. We are launching email verification, public portal and reporting Q1 2019.

  • Nicole - Community Manager

    If folks are interested in David's solution, you can find My Read Receipts in the Zendesk Apps Marketplace


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