Shaykh Fawzān was asked:

What is the ruling of the statement “Jumu’ah Mubāraka” (Blessed Friday) and sending it every friday by mobile messages or (posting) in (internet) forums?

This has no basis, and it is an innovation. It is not permissible to greet the day of Jumu’ah, there has not been anything reported about this, nor is it from the actions of the Salaf, hence, it is a newly invented matter.

Currently the innovators exploit the mobile phones and the internet with that which has been mentioned and they utilise it for the spreading of (other) innovations by these (same) means.

Slightly paraphrased http://www.alfawzan.af.org.sa/node/13651