Multiple emails per voicemail

[theCurRentConnecTion]

I have 15.0.62928.5 installed and running on a 2012 R2 VM. It has been functioning well for over a year, but there is an annoyance with one of the updates (haven't been able to pinpoint which) that I haven't been able to figure out yet. I'm hoping someone here has an answer.

I have voicemails on my extension forwarding to email and deleting from 3CX. This function is working, but I receive multiple copies of the email. Usually four per message, but sometimes more/less. Anywhere from 3-15 minutes apart. I thought at first this was just an issue with Outlook, as there have been documented issues with multiple messages in Outlook 2016. However, after a little more digging, I can see multiple transmissions coming in to my Barracuda email gateway, so the 3CX server is obviously sending multiple copies.

Just now, I was able to watch the progression in real time. A message was left and showed up in the softphone client. I then received the email with attachment, but the softphone client still showed the message. I left the softphone vm display up to see when it was being deleted, and it hasn't yet twenty minutes later, but I haven't received another copy of the email, either. It seems like the messages aren't being deleted properly, so the email gets resent, but I can't verify that and I don't know where to look next.

Any suggestions?

 

[theCurRentConnecTion]

29 minutes later, second email came through. Message still exists in softphone

16 minutes after that for message three. No change in softphone.

4th copy at 61 minutes after the first. In the meantime, another VM has come in and been delivered twice within 2 minutes of each other. Both messages are still listed in softphone.

I'm not going to update after every message, I promise, I'm just trying to illustrate the irregularity.

 

[theCurRentConnecTion]

This was not resolved in 15.5. In fact, it gets worse, as the recorded audio files being sent are about 3x larger than they were before the upgrade. A blank 17s voicemail is now ~300k where it was ~100k before. I can't seem to find any compression/codec settings for voicemail to explain the difference, though.

 

[nb]

Listen could it be that there is a bombardment going on? Can you monitor? The timings you sent show you want to dig deeper. Can you see a pattern? If I were in your shoes, I would seriously not rule this out.

How sure are you that these are same copies being sent VS someone/thing sending the same action 3 times?
How do you explain the same file? The repetitiveness? The copy of the email? The blank file? And now it's getting longer.. Consuming more space as we go. What is the voicemail? Can you upload it? Does it say something?

Maybe they are real calls and there are audio problems? Firewall issues?

Then I would think some timing issue on the server. I dont know. These are the first 3 things that come to mind to check. Dig deeper and update with your findings. I will monitor.