Christian Winter wrote (without reading thoroughly):
> Tobias Sasse schrieb:
>
>> Scott Lowe schrieb:
>>
>>> Yes, the WatchGuard SMTP proxy will interfere with SMTP
>>> authentication (I ran into this problem with another platform/MTA).
>>> The only fix of which I am aware is to use the Filtered-SMTP service
>>> (and then you lose the advantages of the proxy--blocked attachments,
>>> attachment sizes, etc.).
>>
>>
>> Well there are two Mailservers connected to the Firewall. Is it possible
>> that my one connects to the Internet without the SMTP Proxy? I am not
>> interested in the advantages I have from the Firebox, if I could provide
>> SASL + TLS without it %)
>
>
> Do you need the outgoing smtp proxied at all? Otherwise the simplest
> solution would be to disable outgoing for the SMTP service
> and add the "Filtered SMTP" from the packet filters section
> with an allow for outgoing connections.

I should have read the whole thread...
In the "Incoming" filter configuration of the SMTP service
("Modify Service" -> "Properties") you can turn on "Allow AUTH"
on the ESMTP tab.

-Christian