I send a pdf file and it is received as a tif file how do I fix this?

[borencci]

I send a pdf file as an attachement on an email, and it is received as a tif file. How do I fix this?

 

[TegGhola]

Maybe a corporate firewall / security scanner took against the PDF and replaced it with an attachment that just announces that the file is being held in quarantine.

Perhaps try adding the PDF file into a ZIP archive (and ideally put a password on it). That might let it through the security scanner unmolested.