Attachments in Scheduled Reports being renamed as .dat files

[Wayne Richmond]

This is a problem I have just found the cause of so wanted to post it here.

The issue we've been experiencing is some email attachments that have been sent from scheduled reports are being renamed on our mail server (we use IBM Notes), mostly with .dat extensions. This is not the same as the winmail.dat issue others experience.

The name of the file appears to be random, e.g. atto4bge.dat, att09yw3.dat (with Excel files) and atta9r73.pdf (for PDF files). The files themselves are fine if I renamed them with their correct extension so nothing was being stripped.

I realised this wasn't affecting all reports/attachments so figured some of the content might be triggering our anti-virus to do something, however, having disabled it, we ruled that out.

The cause appears to be the length of the file name of the attachment (which is the name of the report). Anything above 60 characters (including the extension of the attachment) was being renamed. 60 and below is fine.

The solution therefore was to rename all our reports so were 55 characters or less (as .xlsx is a default file format, making the total 60).

I suspect there are very few people affected by this but I figured it was worth posting.

[MG Casey]

This was enormously helpful. Solved a big issue for me - thank you!

[quintenvandenb1]

This was indeed the answer what we were looking for. I still don't understand why people with Outlook seem to receive the original filename without any issue and IBM notes seem to convert the file (as of our recent upgrade to Kingston) to a .dat file.

Thank you for your earlier investigation.