We have made use of vbsendmail (recent version, I checked that a minute ago) for years in a commercial ms access / ms sql server / vba project. No technical problem so far.

Problems occur now with a client whose telecom provider is the German Telekom AG, T-Com. Somewhere on the way the mail headers are manipulated in the wrong way and some are interpreted as body text, among them the MIME declaration headers. Thus the base64 encoded sections are not decoded but become part of the body text as well.

I sent some test e-mails to me with vbsendmail via our company's mail server and via my private provider, analyzed the headers, and found that headers are well-formed and the receiving e-mail program successfully decodes the base64 sections and interprets them to be binary. So I should think it's a problem of the t-com servers: fwd02.webpage.t-com.de and mailout04.t-online.de as to the Received headers of the corrupted mail.

But, if the client sends his test e-mail to me via his Outlook-Exchange-system everything works nice. The Received headers show that Exchange passes outgoing e-mails to the same t-com servers as vbsendmail does directly: The Received headers of the non-corrupt mail report fwd01.webpage.t-com.de and again mailout04.t-online.de as stations on the mail's route to me.

I don't know what to conclude from these contradictory findings, any hints?

What's wrong with the collaboration of vbsendmail and that specific server?

Thanks in advance