No MIME-boundary found

[Jeroend]

One of our customer is using Round Cube as mailserver, he created a dedicated account that serves as input for our mail receive function in our POP3 based mail function in our workflow system for graphic industry

Mails always contain only text, after they got received, the body text gets copied to a simple .txt and that file goes into the workflow. No some mails always create an error "No MIME-boundary found". I can't find out why those mails go wrong and other don't.

Does anyone has a suggestion? Thanks

[Jeroend]

Anyone? Please