When email is forwarded to me I don't see the forwarded content but if I reply to the sender the original forwarded content appears in my email after a long expanse of blankness. It only seems to happen with emails forwarded by one sender,
Seems like the sender might want to check for a pending update for their mail client?
See how the sender is forwarding the message in their mail client, too.
If they're using a "forward" button in their mail client, or if they're doing something else to forward.
Otherwise, you're going to become more familiar with MIME-encoded mail messages.
Use the Mail > View > Message > Raw Source, and look at the format of what gets delivered.
Compare what's not working with the message against what is working for others.
Many mail clients will send both HTML-formatted and plain-text-formatted contents in the message.
Two copies of the mail message get sent, one in a MIME block with some formatting, one using text without.
Forwarded content not showing
