received SMS with content "request failed" Today I received two suspicious SMS from two different sender - both from the same provider.
The messages only contained the text "request failed". The numbers do not look like some special expensive numbers.

Can anyone guess what happened?

Is there a way to find out if there is an app which is allowed to send SMS on my phone?

Update: now that I've seen that there is no suspicious app with permissions to send SMS, I try to reconsile the SMS in my SMS history with the ones from my bill. But I noticed that it's hard to get a chronological list of SMS from the build in app - any idea how I can get a chronological list of sent SMS and not conversations?
The last part of your question is easily answered, as there are a lot of permission scanners available on the Playstore. For added benefit, I will just mention one: AppBrain Ad Detector also scans for contained ad modules and more:

 
AppBrain Ad Detector (source: Google Play; click images for larger variants)

As you can see in the screenshots, such an app would turn up in "Has access to your messages", and for sure in "May cost you money".

There are a lot more permission-scanners out there, some even explaining what those permissions stand for and what they mean. Take a look e.g. at RL Permissions, Guardian Droid, or aSpotCat (app by permission) -- and check their related apps for more candidates.