A note on Sending Bulk Mails Using Exchange 2016
You may need to send a bulk of mails for the business need that require sending advertisements to customers.
That will force you to be marked as spammer and blacklisted for some partners also that may cause your mails to be delivered to spam folder not to the normal inbox for the receiver.
In general it will be better to send this bulk of mails through different SMTP relay with different domain to protect your domains from being blocked.
It is not recommended to send the bulk of mails from your domain using a different SMTP relay with unregistered IP which will cause blocking for your domain.
If you will send the bulk of mails from your domain and your servers then the external IP should be registered for your domain through the reverse lookup and SPF record.
For the SPF is a TXT DNS record that prevent spoofing and phishing by verifying the domain name from which email messages are sent, as the receiver use it to verify if the sender IP address is authorized to send using this domain name or not.
You also should make sure all the emails with the correct subject, message bodies, unsubscribe link and adhere to all the local and legal requirements to not be considered as SPAM for other reason.
There is also third party appliance that handle this type of sending the bulk of mails by dividing them to patches and ensure to not consider as SPAM or be blacklisted.
There are also some points you should put into consideration to don’t make this bulk of mails to affect your internal performance as dedicate a Mailbox-CAS server for the sender mailbox.
Also you should locate the sender mailbox on the different database to not affect other users located on the same database.
Finally the best solution again is not to use your normal working domain or servers to send this type of mails and if you have to do that you should put all the last points into your consideration to reduce the probability to be marked as SPAM or blacklisted.
Ratish Nair
Microsoft MVP | Office Servers and Services
Team @MSExchangeGuru
