I noticed a trend with many outreach emails. The email's domain most times different from the official email.
E.g company.com would have official emails with name@company.com but the email used for growth (Sales and Outreach) usually differ, using something similar to name@company.co or name@companyinc.com or even name@e.company.com.
I guess this separation helps reduce the likelihood of the official emails being classified as spam.
Are you sure it's not just scam emails? :D I don't remember seeing this myself except for scams trying to fool you into thinking they are legit.
Nope :)...Most are legit. One can also verify the legitimacy of an email by mechanisms such as Sender Policy Framework (SPF) , DomainKeys Identified Mail (DKIM) and DMARC (Domain-based Message Authentication, Reporting and Conformance). Major email providers do these verifications automatically to verify legitimacy.
For example, see How do I pick a domain name for my Mailgun account?.
Oh intersting, thanks for the link, I think you were right with your assumption about spam :)