Diagnosis of Internet problems

Recognize Internet problems
Tool Collection

A small collection of tools freely available on the Internet to test Internet facilities.

This area is for technically interested customers or if our customer support directs you to this page.

Is your email not reaching the recipient?

Here you can check whether your e-mail address may have ended up in one of the many worldwide spam filters.

Blacklist check

SPF check for your email address

If spam rejections of your e-mails appear, although your e-mail does not appear in blacklists (check see above), this additional check is recommended.

What is at issue? Optionally, a so-called “SPF record” can be stored on our name server. This makes an email address more robust against being mistakenly marked as spam by certain anti-spam filters. A use case would be if external mail campaign senders are to be linked to your email address. The correct functioning of this somewhat cryptic entry can be checked with this tool:

Online SPF Checker

How fast is your actual DSL Internet connection?

Speedtest 1 provided by T-Online:

T-Online speed test

Speedtest 2 provided by AVM (FRITZ!Box manufacturer):

“Zack” – Speedtest

Is your website offline worldwide?

…or is it just a local problem (e.g. of your router / DSL provider)?

Check: Is Website down?

How good is the SSL encryption of your website?

Global Sign SSL Checker

How good is the SSL encryption of your website?

Global Sign SSL Checker

How secure is your VPN connection (VPN Leak Checker)

VPN leak test

Does the domain direct to the correct web server?

Check configuration problems with the domain (name server). Here is a link to a good tool for visualizing domain rooting to find configuration problems with the domain (name server):

Routing test

Here you can see if the correct server IP is shown worldwide (DNS distribution).

DNA test


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