Change of Domain Name

[michaelmartey]

Please  my company currently has a custom domain flash-code.com, which uses office365 for all our mails.

We have rebranded so we are changing the domain name to flashcodesolutions.com which we have already secured

Please is this possible to change to this new domain and still have access to all our existing email.

If yes, any suggestions

Example 

old email : email address removed for privacy reasons

new email : email address removed for privacy reasons

[#2]

Sure, all you need to do is add/verify the domain in your existing tenant, and once that is done, assign email addresses to any and all users you want to cover. As part of the process you can set the new email address as the primary one, but do make sure to keep the old one (as secondary) to avoid issues with replies to older message.

[#3]

@Vasil Michev , thank you but the old domain wont be available once it expires in few days time

We want to fully use only  the new domain for our emails

[#4]

@michaelmartey 

You can configure primary SMTP as your new Domain while old one as smtp (refer to below screen):