While it’s tempting to use multiple email servers to send email, doing so can damage sender reputation.
Large email providers such as GMail or Yahoo not only track the behavior of recipients, but also the sending behavior of each sender domain.
From the beginning of the email activity of a domain, it is tracked which server sends the emails and in which context this server is to be classified.
This forms a reputation history of the domain (and the mail server).
This history is used to derive how many emails a domain is sending, how the sending volume is growing, how the recipient behaves when receiving the email and much more. The domain and its mail server form a kind of person who writes history.
Of course you can move a domain to another mail server over time without causing any damage.
But if you use several mail servers with different IPs at the same time to send emails under one domain, this can be classified as spammer behavior relatively quickly.
Basically, each domain should only send its emails from one mail server with the same IP address over the long term.
This does not apply if you use sub-domains to send different email types! In this sense, a subdomain is an independent domain.
And ideally, sub-domains should send their emails from a different IP address than the main domain, so that there is as little proximity to the main domain as possible.
Campation Post Office™ offers the sending of emails via 4 sub-domains, and you can assign a different outgoing mail server to each sub-domain.
Main domain: this is where you send your individual emails via your SMTP server. You also use this domain and mail server to send transactional emails (invoices)
Sub-domain 1: You send your marketing mails via this domain and the SpeedMail integrated in Campation PostOffice
Sub-domain 2: You send your newsletters and other bulk mailings via another server on which Campation RemoteMail™ is installed