Danil Smirnov:
> Hi!
>
> Is it possible to accomplish a gradual shift of traffic from one mail relay
> to another via postfix?
The randmap() feature comes to mind.
Instead of "relayhost = old.example" or "relayhost = new.example" use:
default_transport =
randmap:{smtp:old.example, smtp:old.example, smtp:new.example}
Pick how many old versus new you need.
Wietse
POSTCONF(1) General Commands Manual POSTCONF(1)
NAME
postconf - Postfix configuration utility
...
randmap (read-only)
An in-memory table that performs random selection. Exam-
ple: "randmap:{result_1, ..., result_n}". Each table
query returns a random choice from the specified results.
The first and last characters of the "randmap:" table
name must be "{" and "}". Within these, individual re-
sults are separated with comma or whitespace. To give a
specific result more weight, specify it multiple times.
This feature is available with Postfix 3.0 and later.