Well, just for the record, if you set 4 minutes or less, you will be receiving 6 emails too.

This issue is getting worse, as, if I invite n people to the event, I get n*6 emails.

I've upgraded my testing environment into 3.2.8 and I am experiencing the same behavior.

Same behaviour here.
SOGo 3.2.7 on Debian 8 + postgres

I've been testing previous versions of SOGo.

3.2.8, 3.2.7, 3.2.6 and 3.2.5 all of them have the same behaviour. 6x emails

3.2.4, 3.2.3 and 3.2.2 are totally broken regarding email reminders. They just don't work at all.

3.2.1 works nice on the email reminders regard.

Do you need more information on my side? Is there any way I can help you to get this fixed? This is a major feature for me and having it broken is starting to be a big problem.

Thanks pabelenda for updating,
i agree this should not be set as minor issue, as it's a basic feature and makes SOGo look unmature for users, IMHO.

pierfu, thanks for your words. I completely agree. Sadly, I cannot bump up the priority nor the severity once created.

I hope soon one of the admins will take care.

We are looking into this.

Many thanks ludovic, really appreciated.

Come back if you need me to test further.

I've tested the 3.2.9 version and I get n email reminders, been n the number of invitees added to the event.

The summary of the report didn't mentioned this, my bad, but I added this fact on an early comment:

https://sogo.nu/bugs/view.php?id=4100#c11587