Mailbox Providers Don't Want To Ruin Your Holidays

You see it all the time. From the highway crew that’s out there taking away a lane or two for routine maintenance during rush hour on a major thoroughfare, to the retail store that closes down registers during peak hours, to the restaurant that has just a skeleton staff of cooks and servers on busy days like Mother’s Day, businesses everywhere deal with their highest volume periods by making sure that they don’t have enough resources to efficiently handle the volume.

What’s that you say? This isn’t the way things are done? Well, of course it’s not; no business responds to peak traffic by cutting its ability to deal with it, and this includes mailbox providers during the holiday season.

Despite a blog post last year by my colleague Christine Borgia, we’re hearing again this year from some customers who believe that mailbox providers change the rules during the holidays, and that they respond to increased sending volume by tightening their throughput rates and filtering rules. The end result of such a policy would be that the mailbox provider would take in less mail than normal at a time when it’s being asked to handle more than normal; as someone who used to work for a mailbox provider, this idea is so counter-intuitive to me that I felt like I had to take electronic pen in hand and blog about it.

Holidays At The Mailbox Provider Can Be A Lonely Place

I spent a number of years working in mail operations and anti-spam at a large North American cable provider, and I believe things that were true for us then are still true for most mailbox providers today. Among those things are:

  • They deploy enough capacity to handle a volume of mail that is substantially higher than normal, but this capacity is not infinite.
  • Their main goal is to make sure that their mailbox holders receive all the mail that they want.
  • A secondary goal is to minimize the time the on-call person must spend fighting fires.
  • The staff who work there all have families, and they, like you, want to spend time with them during the holidays, so they take time off to do so.

The last bullet point there, about staff wanting to see their families over the holidays, usually leads to a “hands off” policy during the holiday period, because there are fewer staff around to help manage the systems. Here in the U.S., that holiday period runs from approximately the Friday before Thanksgiving (or about ten days before Cyber Monday) till the Monday of the first full work week after New Year’s Day. During this blackout window, the rule is usually that no system changes are made unless there’s a hardware failure, because no one wants to break anything, and such policies work. In fact, I once had a VP who observed that we had the fewest number of unplanned maintenance tickets across all of systems operations during these blackout windows, and he openly wondered if perhaps a year-round blackout policy might not be a bad thing. At any rate, the “no system changes” rule would apply to “adding new filter rules” or “changing throughput limits” and other things that would impact inbound mail volume.

Let’s Pretend They Are Out To Get You

For the purposes of argument, I’ll accept the premise that blackouts aren’t in place during the holiday season, and that mailbox providers are willing to make throughput changes to constrict mail flow; I’ll use some simple math here to show why that would be a bad idea on their part.

We’ll say that there’s a mailbox provider than has capacity to handle 10 inbound messages per second, and during the normal part of the year, it’s asked to handle 5 messages per second, so no problem. When the holidays come, it’s now asked to handle, say, 9 messages per second, and it responds by cutting capacity to 8 messages per second. Here’s a timeline of what would happen:

  • 00:00:00 – 9 messages show up, 8 accepted, 1 waiting
  • 00:00:01 – 10 messages show up (9 plus 1 waiting), 8 accepted, 2 now waiting
  • 00:00:02 – 11 messages show up, 8 accepted, 3 waiting
  • 00:00:10 – 19 messages show up, 8 accepted, 11 waiting
  • 00:01:00 – 69 messages show up, 8 accepted, 61 waiting

You can imagine the cascade effect that would happen here, and it would not only impact all senders trying to get mail to that mailbox provider; it would also mean that mailbox holders aren’t getting much, if any, of mail that they want, and that the on-call staff is basically working 24/7 trying to keep its systems functioning under 100% load. Mailbox holders not getting mail and overworked on-call staff are not goals of a mailbox provider; in fact, they’re the opposites of the desired outcomes for the mailbox provider, and so no sane mailbox provider is going to implement policies that get them to this state.

So Why Isn’t All Your Mail Getting Through Immediately?

A mailbox provider will assign a reputation to a sender that is based on its normal sending behavior and the responses to its mail. At holiday time, it’s not unusual for senders to increase their volume, sometimes egregiously so. As we heard last year, it’s also not unusual for sender practices to change at holidays, with lists being expanded by sometimes less than legitimate means. A sender who changes its practices and volume, especially in a negative way, is going to find its reputation will suffer, and it’s not going to get the same treatment it normally enjoys. Mailbox providers know you’ve got lots of mail to send this time of year, and in Christine’s blog post, you’ll find some hints from them on how to maximize your throughput, so long as you play by the rules. If you’re having difficulty this season, go (re-)read her post, and follow the advice that’s in it, and you’ll probably find yourself in a better place.

Happy Holidays!




minute read

Popular stories



BriteVerify email verification ensures that an email address actually exists in real-time


The #1 global data quality tool used by thousands of Salesforce admins


Insights and deliverability guidance from the only all-in-one email marketing solution

GridBuddy Cloud

Transform how you interact with your data through the versatility of grids.

Return Path

World-class deliverability applications to optimize email marketing programs

Trust Assessments

A revolutionary new solution for assessing Salesforce data quality


Validity for Email

Increase inbox placement and maximize subscriber reach with clean and actionable data

Validity for Data Management

Simplify data management with solutions that improve data quality and increase CRM adoption

Validity for Sales Productivity

Give your sales team back hours per day with tools designed to increase productivity and mitigate pipeline risks in real-time