I had an email from equinax saying i had to sign electronically for something called 4506-T what is this? is this legit?

Did you mean "Equifax", the credit reporting agency?

A form 4506-T is a form wherein you request transcripts from the IRS for prior year tax information. A transcript has all the numbers from your tax return, but not the lines and boxes and shading. But transcripts are free whereas exact copies of your tax return cost money.

For this reason, if you are getting a mortgage, it is not at all unusual for you to be asked to sign a 4506-T so that the lender can verify your previous tax returns.

Is this the case for you?

Note that the IRS is not currently fulfilling requests for the 4506-T by mail. If your lender or whoever is expected the results by mail, you would be better served by getting the transcripts yourself online and sending them to the lender (because this still is working).

Please see IRS Get Transcript.