What should we do with a second dedicated IP address?

[Anonymous]

Our organization currently uses a dedicated IP address to manage our email sends, which total several hundred thousand daily outbound.

Generally speaking, about half of our send volume is from regular, daily newsletters to a well-maintained list. The other half is from more ad-hoc messaging like fundraising appeals or special communications that go to a wider, less maintained (and potentially riskier) universe of prospects. Messages in each group go out under two separate brand names.

We have secured a second dedicated IP address with the decommissioning of another business unit, and we hope to use this to bolster our deliverability.

So: What's the best way to go about using the second IP to boost deliverability?

We've heard several different theories on how to allocate sends, and have no idea which might be correct:

• Use one IP for the regular newsletters, and the other for ad-hoc messages. Assumed effects: the newsletter IP has high deliverability, while the ad-hoc IP is weaker; the ad-hoc emails don't harm deliverability for the newsletters, but the newsletters' better reputation doesn't bolster the ad-hoc.
• Use one IP for active subscribers, the other for lapsed reactivation. Assumed effects: the active IP has high deliverability, while the lapsed IP is weaker. Does this approach require us to vary the messaging we send to each group? What's the best way to achieve that segmentation in Marketo?
• Use one IP for each brand. Assumed effects: a wash, since the ad-hoc and regular newsletters are fairly evenly distributed across each brand.

What do you think? Is one of these the best option? Are there unanticipated pitfalls to either approach? Or is there another approach we should consider?

[John_Clark1]

Hi Nathaniel,

In general, it's better to keep your ip reputations as high as possible.  I would recommend the first approach you described, where one ip address is used for the better maintained list, and the other for the ad-hoc emails.  As long as you're not blasting spam at the second group all the time, then your reputation for the second ip shouldn't be terrible, and it will ensure that the leads who are actually engaged with you get the newsletters from the first ip.

John

[Anonymous]

This is very helpful.

Would this approach lead to better overall deliverability than the status quo (one IP address)? Or would it maximize deliverability for the newsletters while hurting deliverability somewhat for the ad-hoc messages?

[Grégoire_Miche2]

There is a fourth solution : drop the second IP address and save money 🙂

-Greg

[Grégoire_Miche2]

If you regularly import databases which quality is variable, I would go for the second solution and reserve the second solution for emails sent to recently imported lists (with a higher risk of unsubscription and hard bounced). Otherwise, I concur with John, #1.

-Greg

[Josh_Hill13]

I like Greg's approach - I doubt you will affect your deliverability much as long as you automate list cleaning properly.

My big question is how can you control that IP send with Marketo? I was under the impression that you could not "choose" the IP it used if you had two. Are you running two separate instances?

[Mike_Reynolds2]

Nathaniel,

Just to add on to what Josh mentioned about automating the list cleaning, here's a doc that could be helpful with that: Maintaining a Directory of Leads Bouncing Emails

[Anonymous]

Josh, there's an IP address selector at the top of the email editor. We use that now to switch between our IPs.