#735 Exchange interface - Davmail sending empty emails when CalDAV events are dismissed

[Miroslav Pavleski]

Example console log:

davmail | 2020-10-18 08:12:15,524 WARN [CaldavConnection-40056] davmail.exchange.ExchangeSession - Overwritten event /users/USER@MAIL/calendar/syrh3HBybI9PngkHDGC8gH68z+NBr15A03I0A9Hk3(LONG GENERATED ID).EML

How to reproduce, using a Office 365 account using Exchange interface:

• Add CalDAV in Thunderbird, without selecting "Prefer client-side email scheduling".
• A number of past accepted events pop-up as reminders (all past probably)
• Clicking Dissmis all or Dismiss causes Davmail to send out empty emails to contacts

[Juha Knuutila]

I had this issue, and it is pretty embarassing to send out tens of empty emails to different people. First time I didn't quite understand what was happening, so I deleted the calender and recreated it, and then it happened second time. Very embarassing. So, I deleted the calendar again, and I have been without one for several days now.

But, are you saying that this issue happens only without selecting "Prefer client-side email scheduling"?

Do I dare to create the calendar once more, now with "Prefer client-side email scheduling" selected, and hope it will not send tens of empty emails for the third time?

Btw. I have this issue in version 5.5.1-3299.

[Miroslav Pavleski]

It hapenned for me 3 times as well :( To at least 20 people each time.

I just wrote the exact conditions how it happened the last , third, time., for the developers to be able to reproduce the issue.

I am not sure that with "Prefer client-side email scheduling" selected , emails will not be also sent ! So please don't test with actual people contacts :)

[Mickael Guessant]

Sorry for this, can you please confirm that this happens with latest Thunderbird version 78 ?

Something probably changed related to event reminder dismiss, as current code is specific to custom Mozilla attributes.

=> need to check actual event content on dismis to understand what has changed in TB 78

Please also make sure that davmail.caldavAutoSchedule is set to true in DavMail when Prefer client-side email scheduling is unchecked in Thunderbird

[Juha Knuutila]

At the time this happened for me, I was running thunderbird-78.2.1-1.fc31.x86_64. I now have thunderbird-78.3.1-1.fc31.x86_64, but I have not tried davmail with that anymore.

And yes, I had:
$ grep davmail.caldavAutoSchedule .davmail.properties
davmail.caldavAutoSchedule=true

[Fabio F]

Me too. Exactly the same problem!
TB78.4.0
davMail 5.5.1-3299

davmail.caldavAutoSchedule=true
Prefer client-side email scheduling unchecked

Please, fix it.
In the meanwhile disabling davmail.caldavAutoSchedule can I temporary solve?

[Miroslav Pavleski]

For the record, for me also the davmail.caldavAutoSchedule was set to true when those messages happened

[Nicolás Victorero]

Happened to me also (or something quite similar), log lines look different tho.
TB 78.4.2 (64-bit)
davmail 5.5.1-3299
No reference to davmail.caldavAutoSchedule in my davmail.properties
Messages sent after clicking Dismiss, only to the creator of the meeting, not everyone (creator was a person outside my organization in case that matters).
Deleted the event directly from my OWA calendar, but it came back again. So just unsubscribed from the calendar.
I have this lines in my log corresponding with the moments i sent the unwanted emails:
2020-11-19 07:59:07,545 WARN [CaldavConnection-34982] davmail.exchange.ExchangeSession - Overwritten event /users/xxx@xxx.xxx/calendar/AAMkAGRkMWRmZGNmLTU4YTUtNDU1Zi1hYTMyLWQ2Mzc4YjgxYjRiMgBGAAAAAABcSxdKQ2OiSKzEbaNwPWvxBwDAzY9ijD6uQL3LE19PhCO_AAAAL7SVAABPTBDuP6ajTZykLk1d7AL9AABDV6iHAAA=.EML

[Fabio F]

The milestone field of this ticket must be updated to 5.5.1.
Is this still an active project?

[Mickael Guessant]

Another setting to check is:

davmail.caldavRealUpdate=true

In next version I plan to completely remove the old delete/add event mode that triggers unwanted behaviours with scheduling.

[Miroslav Pavleski]

Thank you Mickael. If I understand correctly, if we set davmail.caldavRealUpdate to true, the behavior should not happen?

[Mickael Guessant]

I can't be hundred percent sure as I have not reproduced it myself yet.
However in this mode DavMail should be able to detect "Dismiss" or "Snooze" events and in this case update only the mozilla custom field on event.

[Fabio F]

I'm using davmail for windows. How can I set devmail.caldavRealUpdate=true?

[Chris Arnott]

I've had exactly the same issue having just moved to thunderbird 78.7.1 (from 68). A while after adding a calendar I got a whole stack of notifications for past meetings, clicking dismiss results in emails being sent out to meeting organisers. The caldav section of my davmail.properties is

# override default alarm sound
davmail.caldavAlarmSound=
# retrieve calendar events not older than 90 days
davmail.caldavPastDelay=90
# EWS only: enable server managed meeting notifications
davmail.caldavAutoSchedule=true
# WebDav only: force event update to trigger ActiveSync clients update
davmail.forceActiveSyncUpdate=false

Davmail is version 5.5.1-3299

Can anyone confirm if setting davmail.caldavRealUpdate to true resolves this issue?

[Antonio R]

I experienced this with 6.0.0-3375 . There may have been some network connectivity issues that precipitated the event -- the emails were sent basically as soon as I tried to dismiss the alerts.

I've disabled calendaring in Thunderbird in the meantime.

I think a mitigation may be to, if there are a bunch of notifications visible that shouldn't be there, quit davmail before touching Thunderbird. But, I have not tested this (and am not willing to, since I've already accidentally bothered too many people with this today).

[Lieven Vandevelde]

I also have the problem of unwanted mails with these versions and settings:

DavMail 6.0.1 ( on openSUSE Leap 15.3: 6.0.1-lp153.6.1)
davmail.caldavAutoSchedule=true
davmail.caldavRealUpdate=true

Thunderbird 91.5.1
Unchecked "Prefer client-side email scheduling"

[Jeff H]

Hi,

Not necessary to respond to this, but providing my experience in case it helps troubleshoot the issue:

This problem (dismissing meeting reminder sends email to organizer) started happening to me several weeks ago (and I have now made the calendar read-only). I am using Davmail 6.0.1-3390-1, Thunderbird 91.5.0, & KDE neon 5.24, although I don't which versions of these were in place when the problem started. I was not having any problem earlier in the year and I use the software daily.
"Caldav automatic scheduling" is checked in Davmail Gateway Settings.
"Prefer client-side email scheduling" is unchecked in Thunderbird.

I don't know if it is related, but at about the same time as the above issue started, I also started getting a new error in Thunderbird: Message "Timezone Errors See Error Console: Unknown timezones are treated as the 'floating' local timezone". The message appears every few minutes, unless I quit Davmail.

Probably unrelated (and not too important), but my tray icon has lost some functionality such that right clicking doesn't bring up menu anymore, although left clicking does open window.

Let me also mention that I donated 10Euros(US$12.08) on Nov.9 via Paypal, without including email.