On 18 Oct 2018, at 8:44, Richard Salts wrote:
On 18 October 2018 9:44:35 pm AEDT, Manuel Mely <[email protected]>
wrote:
Hi there,
I'm looking for some information related to MTAs usage statistics
worldwide. In other words, i would like to know how many postfix (and
other
MTAs) are deployed out there, in the wild thing called "The Internet"
:)
Any suggestion?
http://www.securityspace.com/s_survey/data/man.201809/mxsurvey.html
It should be noted that this survey is skewed by its basis in a survey
of web servers and exclusion of unidentifiable MTAs. It appears to be
counting every cPanel-managed website using the default cPanel
configuration for mail exchange as a distinct MX, and that counts a
whole lot more Exim 4.91 instances than actually exist. DirectAdmin and
ISPManager also appear to only offer Exim, but are not as widespread. In
the same vein, Postfix may be over-represented because it is the most
commonly used MTA for Plesk-managed websites, and the only one supported
in some less common web control panels.
This points out the basic difficulty in doing MTA surveys. It's
impossible to know what MTA you've connected to in many cases, it is
often impossible to know if it's the same instance you've already
connected to on a different IP, and if (as it seems for the above
survey) you don't de-duplicate targets by IP but only by name, you may
talk to the same MTA on the same IP many times over by chasing a bunch
of different MX names. Beyond that, you also have a reverse problem of
very large mail hosters masking scores or hundreds or maybe thousands of
MTA instances behind some combination of round-robin DNS, load
balancers, and anycasting making them look like a handful of machines.
And finally there is the Zen question of MTAs: if a Plesk-managed Qmail
instance that hasn't been able to deliver mail for a decade is the MX
for a domain with no addresses that anyone cares about, is it really an
MTA?
