Is there a need to throttle large Marketo email blasts? Or is this automatically done?

[Anonymous]

Hi, I'm about to schedule a large email blast (about 80,000 leads), and I'm curious if it's actually necessary to throttle the blast... I.e. 10,000 messages every 3 hours, etc.

Or, does Marketo naturally throttle email sends within safe limits? I've read somewhere in the discussion forum about this, but that was a while ago... want to make sure it's still true.

Overall, I just care about good deliverability. I don't care about how many messages go out per hour. As long as we get good delivery rates

Thanks!

[SanfordWhiteman · Accepted solution]

Marketo will not automatically tune email sends to "safe" rate limits for individual recipient domains for a variety of reasons. One is that there's no way to manage what rate limits are in place (even a literal SMTP 4xx "Rate limit exceeded" response does not usually tell you what algorithm was used to calculate the limit).  Another is because it would impact Marketo's ability to serve massive outbound volume if everyone requested a trickle effect.

There are many threads here about how to manually split up sends using random samples and/or alphabetical splits. Note some of the recommendations are frankly nonsensical (spacing things out by 5 minutes, for example, is not going to make a diff). But you should find lots of legit guidance.

We have been bitten by some extreme rate-limiting, er, limitations and have relayed some Marketo email through our own servers in order to slow it down.  That is an extreme option.

[Anonymous]

Thanks!