Photo of Devon McCarty


ROCK v13 Communication Attachment sporadic issues

We recently upgraded to ROCK v13 (from v12) and since then we have had some odd issues with communication attachments sporadically working.  We have had some emails get sent where the attachments work for some people and not for others.  Prior to v13 we did not have this issue.  I have explored Mailgun logs for one of the people who sent a communication and their "Test Email" to themself had the attachment listed with a proper size attribute, but when they sent the final communication the log record showed the attachment but the size for it wasn't correct.  So, in their email program they could open the attachment for the test email, but not the final communication.  Then they received word from some people on that communication that they were able to open the attachment just fine while others were reporting it wasn't working.

Now I noticed that with v13 there was this change "Updated communication system and transport to use multiple threads when sending communications and when processing each recipient."  A theory I have is, I'm wondering if the multiple threads may not have proper access to the attachment file and that is why it is working for some and not others.

Again, we didn't have this issue prior to v13 (we are the latest at the moment, v13.3).  Any help would be greatly appreciated.

Update: 2022-05-04 at 5pm
After exploring this a little more in Mailgun, it doesn't appear to be an issue with email hosts.  I found two logs with the same mx-host and one had an attachment size of "162" and wasn't able to open the attachment, while another had  an attachment size of "404152" and was able to open the attachment.  In mailgun, both log entries were the same minute.  So my theory still is that one Rock thread could properly send the attachment, while the other for some reason couldn't.

Update: 2022-05-07
Thank you @Michael Roth for your suggestion to use Mailgun API and @Jonathan Anderson for also verifying this with using SendGrid API. We made the switch from SMTP to the API and haven't had this issue occur.

Update: 2022-06-17
Notice issued from ROCK for an upcoming change: "Starting in Rock v14.0 the SMTP transport is no longer supported. The newer HTTPS transports, and improvements in the way Rock uses them, have significantly boosted the speed at which messages to a large number of recipients can be sent. The continued use of the SMTP transport works against these performance improvements and has created some reported issues with corrupted attachments. The new transports are very easy to use."

  • Photo of Michael Roth


    Hey Devon,

    We have run into this with 1 other church and chased it down to a bug when you use SMTP with mailgun.  The fix for the church that was have exactly the same issue as you was to switch to the API Transport.  Let us know if that fixes the issue or not.

    Michael Roth

  • Photo of Jonathan Anderson


    We upgraded to v13 this week and have been having similar issues with email attachments. We were using the SendGrid SMTP transport and after finding this thread I have changed over to the API. This seems to have fixed the issue for us.

  • Photo of Jim Michael


    Hi Devon-

    While I haven't heard of this issue until your post (and we're not in production with v13 yet ourselves, so wouldn't see it) it does sound like something isn't right. My suggestion is opening a Github issue for this which will get in front of "dev eyeballs" way more than this Q&A post will.

    We can't yet rule out that it's not something specific to your system (after all, v13 has been out a while now and I'd think we'd be hearing about it from lots of orgs if it was a general issue) but it would still be good to get it in the system and we could point people there that end up seeing the same thing (e.g. confirming the issue). I would also specify what your _Concurrent Send Workers_ in your email transport is set to, in case it's different then the default of 10.

    You can submit a Github issue here

  • Photo of Steve Pham


    We had the same issue moving from v12.7 to 13.5.  All of our email communications that were being sent out with attachments were corrupted and would not open.  Upon posting on the Rock community about the issue and Derek M responding with this thread here, I switched our comm transport from SMTP to HTTPS API for our Rock to MailGun configuration, which fixed our corrupt attachments issue.   

    Thank God for the Rock community!  :)