Backup mail server
A backup mail server or, better, a backup mail
exchanger is an essential ingredient of any at least half-way serious
business email solution.
If you operate an in-house email server for the direct receipt of email
via MX routing on a dynamic IP, then the existence of a backup-MX is
In the Business A and higher tariffs you can configure your own
backup-MX with us.
In the Business C and higher tariffs we offer you the use of our
backup mail exchanger. For private use, the Business C tariff with
an expiration time of 30 minutes might be half-way good enough. For a
business environment we recommend at least the HeartBeat A tariff if you
want to safely use an in-house email server.
Let's assume that, due to a technical problem with your internet
connection, your email server is no longer connected to the internet.
You can no longer directly receive emails. In order to prevent that
emails which are addressed to you are not returned to the sender, our
backup mail exchanger comes into action and stores the emails
temporarily. When you have solved your problem and are back online, your
emails are automatically delivered by our backup mail exchanger. The
emails are stored for up to 5 days on our backup MX server before they
are returned to the sender as undeliverable.
Why a HeartBeat tariff?
Let's assume that your internet connection is disrupted and your last IP
is dynamically allocated to another internet user.
If we don't neutralise your account within a few seconds, i.e. configure
your account with an IP to which there is no mail server connected, then
emails addressed to you will be sent to someone else's server.
3 situations can now occur:
Emails cannot be delivered and are returned to
the sender with an error message, unless you make use of our
backup mail exchanger service.
Your "former" dynamic IP was assigned to another
customer of your internet-access provider (e.g. T-Online).
Your emails can then reach his email server (if he is running one, otherwise
see a)). He rejects your emails with the error message "User unknown".
This certainly does not leave a positive impression on your customers.
As described under b), your emails reach someone else's
email server which, however, is configured so that it can receive them
(default in the case of Tobit David)!
Critical emails meant for you land in someone else's hands!
Our backup mail exchanger stores your emails for up to 5 days before
sending them back to the sender with a message saying that they cannot
The maximum email size is 15 MB per email, with no further limit on the
total number of emails.
A very conservatively configured spam-blocker protects you against most
spam if your email is routed via our backup-MX.
If you would like to safely operate an in-house email server which is
connected to the internet via a dynamic IP, then DynAccess is your first
choice. For only we have the technique of the HeartBeat tariffs which
make the use of an essential backup mail server possible.
We are not stating, however, that a backup-MX is not necessary on a