On Sat, May 23, 2020 at 08:39 AM, Thomas Gruber wrote:

Or if you want to be really generous, a warning reply - like „please don‘t send emails without subject“

I think even that is too much if a relationship has not yet been established. People DO send blank emails to subscribe, unsubscribe, etc. It's not standard practice or in any way required that all emails have subject lines.
 
--
J

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