[pfx] Re: Rejecting messages with Multiple From addresses (and no Sender)

On Thu, Feb 13, 2025 at 06:51:26PM -0500, Wietse Venema via Postfix-users wrote: > Maybe. First you need to be clear about what you > mean with multiple From addresses: > > Email with: > From: "f...@example.com" Exchange accepts this. > Email with: > From: "whatever" Exchange accep

[pfx] Rejecting messages with Multiple From addresses (and no Sender)

Hi, Microsoft Exchange Online rejects messages with multiple From addresses if there's no Sender address specified per https://learn.microsoft.com/en-us/exchange/troubleshoot/email-delivery/ndr/fix-error-code-550-5-1-20-multiple-from-addresses This is in relation to https://www.rfc-editor.org/