If you're a freelancer, sole trader, home worker looking for work (for example as a contractor) then you would want a single permanent email address for this purpose. It's probably best to register a domain in this case. Depending on the jurisdiction you're in, you might want a specific name to trade under anyway, even if you don't have a registered company. You can purchase a domain name without having a website and connect it to a host or use Google for work app or yahoo professional email they offer you professional email connected to your domain name.
Your email doesn't need to be your own name, but for a professional look and credibility about your company as a freelancer, sole trader or home worker if you have a business name this structure of email email@example.com is ideal. Or your national equivalent of .com: .co.uk in my case firstname.lastname@example.org. My business email address relate to my business name and bear my personal brand name and in line with my domain name.
There are a couple features available through Gmail, ymail, yahoo email accounts that may help you with your email name creation decision. The first is the ability to forward your emails from this newly created email address to an existing email address so that you gain access to emails more quickly. The issue that may arise is that you may forget to log into the email account with the name you provided causing you to send an email from a less professional or desired email address. The other option is to simply create a filter to send emails to a selected email address to alert you to the fact that an email was sent to you regarding a job position you are seeking.
Here 6 ways to create a professional email
Pick an address that you can stick with - your current copy of your resume may last a lot longer than you think. The email address is an ideal way to contact someone about a job, so make sure you'll be regularly findable at that location. Things to avoid here: a friend's server, domains you think you'll leave within 3 years, work addresses that will go away when you leave your current position.
Gets good spam filtering - resumes are public things, they get spread far and wide. That's great for your career options, bad for spam. Make sure you have a reasonably decent spam filter on this account.
Set up your account for frequent checking - many fields and recruiters expect a turnaround time in hours to days, not weeks. Don't set up an account that you aren't prepared to check regularly.
Avoid references to race, creed, gender, religion, or particularly wild things in your username - john.smith.programmer479 is better than wildandcrazysaturdaynightspecial or BT67854321@betty.com no matter what you read into that... it's just not professional.
Avoid very long, typo-prone cases - Realize that in some cases you'll have to hand write the email address or that it may end up being hand-typed by a reader - a few numbers are not a big deal - john.smith.394 is fine. But something with a very long string of digits, or cases of highly typo prone usernames are something to avoid as well as (Il|1i#p0 - are easily confusable with each other - particularly in some styles of hand writing, as are oO0 - easier to figure out from context - if the context is clear).
Do connect it with anything professionally related to you, don't connect it to anything that makes you look unprofessional - the classic being don't use a username for your email that is easily connected to your drunken pictures on Facebook or Instagram. But the positive view is that it's not so bad if, for example, your username is easily connected to great questions and answers on LinkedIn.