Sending Outlook Email doesn't throw error but doesn't sent mail either

I’m currently using the outlook message to give a report to the business after a specific task has been done. Here is the code :

and the catch part :

I’m using the outlook activity in a Retry Scope because sometimes Outlook throw error about not being available.

The issue I have is that, often, the last log message (saying that all went good) is executed, but no mail is actually sent. The mail is neiter in Sent items or Sending Outbox, and no error message (not even the one in try/catch) is generated.

Do you have any idea of what is happenning or how I could debug this ?

@Smixi Can you test just the Oulook Mail Message Separately in a Sequence, with some dummy message and check if it Works?

It does work most of the time. For 35 mails, 2 mails were not sent.

@Smixi Is anything dynamic in the Mail? Like are there contents that may change for different situations like the To Address or Subject or the Mail Body ?

The three are changing. But for those unsent mail, I added them to transaction again, and again, some of them got unsent, but some of got sent, so the content shouldn’t be an issue.
Note that I’m joining a file in the mail.

To complete information, I just ran the process on 2 unsent mails, one got sent, the other not.
By looking at Trace file, there were not error during the Send Outlook Mail Message activity (status = Executing, and then status = Closed) and even no Faulted activity in the whole process.

@Smixi Seems Strange :sweat_smile:, Did you try Sending the mail Manually to that mail which was not sent?

No, I’m in production environnement and cannot do that ^^.

@Smixi Have you Logged the To Address, Mail Body and the Filename that you are attaching in the logs?

Yes, but I cannot share them (they are in proper format, but for confidentiality issue can’t post it). (and it doesn’t change that some unsent mails got sent afterward, and vice-versa).
Same with the mail, but it’s somehow constant (only one part of the mail is changing through a .replace operation.

Facing similar kind issue … bot is getting hanged after processing certain transaction. Purpose of the bot is just to sent emails with attachments and attachment is getting created at run time … and while send the email via SMTP it’s getting hanged …