virtdomains: userid?

Scott Balmos sbalmos at
Sun Nov 27 17:34:05 EST 2005

Nope Bill, sorry. As was noted in my thread, it looks to be a SASL 
issue. Because some SASL plugins require a hostname, rather than IP, 
SASL apparently does a reverse DNS on every connecting IP.

Maybe I'll move a request over to the SASL list to look into whether the 
reverse DNS can be on a per-enabled-plugin basis (thus if I only have 
enabled plugins that don't require reverse DNS, it doesn't occur). But 
my personal problem with it was resolved - I kicked my ISP in the rear 
and got them to fix their DNS setup. Being a local cable operator, they 
actually do respond to customers' technical requests (*gasp*). :D


Bill Kearney wrote:

>Would this help your reverse DNS lookup trouble?  Or will using the
>unqualified name still trigger a reverse lookup?
>It doesn't appear to help my situation, in that I'd like logins without a
>qualified name to use just the bare username and NOT append a realm onto it.
>Is this possible?
>Configuring Virtual Domains
>    Virtual domains is the practice of hosting a service for more than one
>    domain on one server. Cyrus IMAP has the ability to host IMAP/POP
>    mailboxes for multiple domains (e.g. test at and
>    test at on a single server or Murder.
>    In order to accomplish this, Cyrus needs to know which domain to look
>    in when a mailbox is accessed. There are two ways in which Cyrus can
>    determine the domain:
>      * Fully qualified userid - the client logs in with a userid
>        containing the domain in which the user belongs (e.g
>        test at or
>      * IP address - the server looks up the domain based on the IP address
>        of the receiving interface (useful for servers with multiple NICs
>        or using IP aliasing)
>    Both of these methods are active if the virtdomains option is set to on
>    (or yes, 1, true) and can be used in conjunction with one another. If
>    the virtdomains option is set to userid, then only the first method is
>    used. Note that a fully qualified userid takes precedence over a domain
>    obtained from the IP address.

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