Choosing a dedicated IP address or not to send messages via Postal depends mainly on how many messages you send.
We have strict rules to prevent Postal from being used to send unwanted mailings. However, when you use a shared IP address, many spam markings of other people’s mailings could in the long run affect the reputation of the IP address, and therefore your mailings.
With a dedicated IP address, you do not risk being affected by others’ mailings. However, it costs a little more per month.
We recommend using a dedicated IP if you send more than 100,000 messages per month. Since you are the only one using the IP address, you need to send some messages to maintain a good reputation. Sending too few messages can be as bad for your reputation as sending too many. Sending an even number is the key to a good reputation.
However, a shared IP is best suited for you if you send less than 100,000 messages per month, or if you send a few from time to time. Sometimes many, sometimes few. Some recipients may otherwise see your peaks as spam.