Why It Went to Spam

Questions / Reputation and rules

Do I need a dedicated IP address for email?

Short answer

Probably not. A dedicated IP address is a sending address only you use, so only your own habits shape its reputation. It needs steady, fairly high volume to work well. If you send small or uneven amounts, a well-run shared address is usually the safer choice.

The detail

Your email leaves from a server, and that server has an IP address. Mailbox providers keep a track record for that address. Our page on sender reputation explains how.

Shared or dedicated

On a shared IP address, many senders use the same address. Email services usually start you here. Amazon's SES guide says new accounts send from addresses shared with other users by default.[1]

On a dedicated IP address, only you send from it. Amazon describes these as reserved for your exclusive use.[1]

Two boxes. On the left, a shared IP: you, Sender B, Sender C and Sender D all use one address and one shared record, so neighbors can hurt you. On the right, a dedicated IP: only you use the address, so only you can hurt your own record.
A shared address has neighbors. A dedicated one doesn't.

What each one costs you

Sharing has a catch. Google says the activity of any sender on a shared address affects the reputation of everyone on it.[2] A careless neighbor can hurt you. Our page on why emails go to spam covers this.

A dedicated address removes the neighbor. But then your reputation rests on you alone. Amazon says an address that sends steady volumes over a long time usually has a good reputation.[1] A new dedicated address has no history, so you must warm it up. Amazon says to send a little more each day.[1]

Why small senders usually shouldn't bother

Amazon's guide says that if you won't send large volumes regularly and predictably, use shared addresses.[1] It gives a reason. Most providers only track an address's reputation once they get a lot of mail from it.[1]

So a quiet dedicated address may have no reputation at all to build on.

What a dedicated address asks of you

It isn't set and forget. Amazon says to send several hundred emails in a day, at least once a month. Do that for each provider you want a reputation with.[1] Miss that, and the address may stay unknown.

It also gives you something. On a shared address, Amazon says your reputation is set at the account level and can't be split up.[1] A dedicated address lets you keep different kinds of mail apart.

A quick way to decide

  1. Do you send big batches at steady times? A dedicated address may suit you.
  2. Do you send now and then, or in bursts? Stay on a shared one.
  3. Do you send different kinds of mail? Think about splitting them instead. Our page on sending from a subdomain shows how.
A question: do you send large amounts, regularly and predictably? If yes, a dedicated IP may suit you, with a warm-up planned. If no, a shared IP is usually the safer choice. A note says clean lists and consent come first either way.
A rough guide to choosing.

Whichever you pick, a dedicated address won't fix bad habits. It only makes them yours alone. Check your bounces and your list first.

Sources

  1. Dedicated IP addresses for Amazon SES, Amazon Web Services (SES Developer Guide) (accessed 2026-10-31)
  2. Email sender guidelines, Google (Gmail Help) (accessed 2026-10-31)