Re: [exim/exim] [Bug]: smtp transport outbuffer[4096] too small for XOAUTH2 AUTH commands, causes fatal "overlong write_command" (Issue #3208)

On Mon, Mar 23, 2026 at 10:09:28AM +0000, jgh via Exim-dev wrote:
> 
> Using it to generate a plaintext-protocol string to be sent to the server seems unusual, though I have no idea what
> the XOAUTH protocol might required.
> 
> The XOAUTH2 protocol public name is not one that is usually used in combination with Exim's plaintext authenticator driver; that driver has no special knowledge of that protocol. Why do you expect it to function?

Please see https://gitlab.com/clearfocus/oauth2_exim for one example.
However I have not encountered any overflowing in my use.

> 
> While it may indeed be possible to feed a large-enough string in, via this authenticator driver, to hit the internal check in the output path - it is far from obvious that this is a bug or needs fixing.
> 
> ---
> View it on Exim Forgejo ( https://code.exim.org/exim/exim/issues/3208#issuecomment-239280 ) or reply to this email directly.
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