Here are the list of Do’s & Don’ts to take care of when deciding your ‘from’ email id & its domain/sub-domain.
Email services perceive track reputation primarily at SUB-DOMAIN level. So if the reputation of promotion.root.com declines, you do not face any deliverability challenges on support.root.com. Therefore, you can following these guidelines -
For transactional emails - Create a separate sub-domain only for your transactional mails.
For marketing emails -
If your root domain has good open rates, and maintains bounce & spam rates within limits, you can continue using the sub-domains on your root.
If in the rare case your root domain reputation has suffered, you can use this workaround. Create ANOTHER root domain, with same name but different "tld". And use the subdomains of the new root for your mailing needs. Example - if flickzee.com is your root domain with questionable reputation, use a sub-domain on flickzee.net. Also don’t forget to point flickzee.net to flickzee.com
As a rule, never keep transactional email sub-domain same as marketing email sub-domain.
As for cold emails - Never keep the same root domain.
If you want to increase your chances of landing in Gmail Primary Inbox,
It is advised not to use marketing related name & sender ID, like email@example.com or firstname.lastname@example.org. Better to put it in the name of someone in the team, like email@example.com.
Same goes for the name as well. Obviously, keep your sender name same as your email ID. Example - Put John as name if the from email ID is firstname.lastname@example.org
Custom domains significantly help in increasing your delivery & open rate. Thus, use the one in which you can setup a custom domain. That means if you are already using blog.your-site.com for hosting your blog, you shouldn’t be using this as a "from domain", since you can’t setup a custom domain on it.
This goes without saying, but never use generic GMail, Yahoo or Outlook email ID
Complying with regulations
You're required to include your contact information, including a physical mailing address, inside every promotional email you send in order to comply with anti-spam laws such as can-spam and CASL
Pro-tip: The 'From name' cannot contain 'commas' and 'periods'.