Question phpmailer : attachments sent with it don't arrive on my plesk emails

[LaurentR2D2]

Hello,

A mail was sent with an attachment to an email adress on my server using phpmailer. The mail is arrived but without the attachment. The size of the attachment is little (5 Mb) and the limit set for my mail server is 200 Mb. The mail has been sent to a gmail adress and it has worked. Is it a setting on Plesk that I have missed which makes that it doesn't work ?

Thank you