I presume you mean the pdf is ok via webmail (and not corrupt) and you can view it ok in webmail.
I previously only heard of this issue with eg: icloud accounts (if these emails are coming to you via an icloud acct) where there was previously a bug on icloud and eM Client did a workaround to fix that.
If its not related to icloud could be a similiar thing from your specific email server causing the same issue. Either way check that you have the latest version of eM Client for Windows or Mac via the ver history page. https://www.emclient.com/release-history . Also if you do install a later version of eM Client, first make a backup via “Menu / Backup” just incase you have to restore for any reason.
Note:- If you already have the latest version and you don’t have an icloud acct, then can you advise which mail server you are receiving mail from to see if other users are also having this same issue.
Yes can view & download the PDF OK via webmail (VPOP3)
We are on the latest version of EM Client
Emails are not coming from or connected to an Icloud account.
We have users who work in a Terminal Server environment who it affects. My own account is a stand alone PC. When a corrupt email is received I have to take a copy of the original email from our email server & drop it into my EM Client account, copy the PDF attachment from the email & move it into a shared folder. The TS user can then view the PDF & send out to customers without issue.