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What about if %u were permanently changed... but %n and %d left with the original values. It would seem that those people relying on the behavior of %u being stripped would not likely be using nor caring about the values of %n and %d since they are essentially discarding them anyway? That way you have %u acting as the "authentication username", and %n and %d containing the "username" and "domain" (as sent by the client).

Maybe, but it's still an incompatible change that could break existing installations. Also you're thinking only about the case when you want to drop the domain. auth_username_format can be used for a lot of other things as well. It gets confusing if %n and %d sometimes change, but sometimes don't.

True, I hadn't thought about that.

I'm not much of a C programmer especially in the scheme of something as complex as Dovecot... but if you could be so kind as to point me within a couple of metres of the location in the code where the changes to %n and %d get made by auth_username_format, I'll try to patch something myself locally on my servers to get the result I need for now and leave it up to you to decide if it's worthwhile adding additional variables at some point down the road to expose the original values.

Cheers,

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Mike <<<<<