I need to add code to allow my squarespace hosted site link to my email provided by 123reg -HELP

What a nightmare, So 123reg messed up my email, which has always worked ok with squarespace until now. They have migrated my email to 365Office, and told me I need to add the following to my page - somewhere.

No phone help from Squarespace, nothing on their  site, just twitter support, no use to me at all as i dont use twitter, please can some one help?!! This is my business email, and I need access asap, thanks.

 add the below TXT record to verify your domain with Microsoft:

TXT name: @ or skip if not supported by the provider. TXT value: MS=ms12586877 TTL: 3600 or your provider default.

I'm in the same boat. Did you get a solution?