Marriage allowance

I received an e-mail today relating to my registration for the above allowance (this subject came up on the forum some time ago). I was told that we would be amongst the first to be considered but before that could happen we would have to provide evidence of eligibility and give details of passports,driving licence,credit card details or mortgage statement. I have always baulked at giving any info such as this either online or on the phone as identity fraud is very common these days. Has anyone else received this e-mail and what are your views about giving this info? Is it a genuine website I ask myself.