Word to the Wise

My ISP might get blacklisted

The last of seven in our occasional series on why ESPs need, or don’t need, lots of IP addresses to send mail properly.

I want to avoid network outages

Number six of seven in our occasional series on why ESPs need, or don’t need, lots of IP addresses to send mail properly.

I need to dodge filters

Number five of seven in our occasional series on why ESPs need, or don’t need, lots of IP addresses to send mail properly.

I need to deliver my mail fast

Number four of seven in our occasional series on why ESPs need, or don’t need, lots of IP addresses to send mail properly.

I need IP addresses to avoid throttling

Number three of seven in our occasional series on why ESPs need, or don’t need, lots of IP addresses to send mail properly.

I need IP addresses to handle the volume

Number two of seven in our occasional series on why ESPs need, or don’t need, lots of IP addresses to send mail properly.

I need IP addresses for reputation

Number one of seven in our occasional series on why ESPs need, or don’t need, lots of IP addresses to send mail properly.

Why do you need so many IP addresses (part 2)?

In my last post I discussed the background as to why an ISP will require their users to use their IP address allocation efficiently. I also mentioned in passing that I’d discussed ESP address allocation with both ESPs and ISPs recently.
The ESP was talking about assigning a couple of dozen IP addresses to each customer, because they might be useful for spreading load and it would provide some flexibility for moving from one IP address to another if one should get blocked. And IP addresses are pretty much free. They were wrong.
The ISP was considering an application for 750 IP addresses from a new ESP customer. They assumed that there was no possible reason other than snowshoe spam for an email related customer to need that many IP addresses. While I suspect they may have been right about the specific potential customer, the general assumption was wrong.
I’ve seen a lot of reasons given by ESPs for why they need so many IP addresses:

Godzilla