Scott, Hmmm, I believe the leading space is how "folded" (extra long header lines) are denoted so Google is likely viewing the MIME line as an extension of the from line.
-- Larry Smith lesm...@ecsis.net On Mon September 18 2023 09:53, Scott Mutter via mailop wrote: > We're seeing an increase of errors from Google's mail servers complaining > about multiple addresses in the From header. But these messages do not > have multiple addresses in the From headers or multiple From headers. > > Best I can tell, this seems to be caused by additional spaces in some of > the headers, I suppose the header immediately following the From header. > > I'm not really sure who is at fault here. Are leading spaces in mail > headers allowed? > > Headers formatted as: > > From: Name <em...@domain.tld> > MIME-Version: 1.0 > > Generates this multiple addresses in From header error. > > Headers formatted as: > > From: Name <em...@domain.tld> > MIME-Version: 1.0 > > Does not generate this error and messages are sent through. > > (In case the formatting of this message does not portray the issue > correctly, there is a single space before MIME-Version: 1.0 in the message > that generates this error) > > I'm not sure if a leading space in a message header is proper. But I would > also kind of lean towards this being a wrong regex being used by Google's > mail servers to detect multiple addresses in the From header. > > Anybody else seeing this or have any insights? _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
