Email throttling is controlling the amount of email messages sent to one ISP or remote server at one time.  Sometimes ISPs block messages when a high volume is sent by one sender at one time because they might be concerned its spam. 

Vuture provides a configuration to limit the number of emails that are sent to specific domain in a given period of time.

To turn it on go to "Admin.System.Emails" then change the default Throttling Gap. The recommend value is 1 which means that the system will wait 1 seconds between each email sent to the same domain. 

Exclude specific domains from the throttling process during an email send

If you would like to exclude specific domains from the throttling process, Vuture has a system configuration in which you can add comma separated list of domains (the feature matches on exact domains, so you would need to include sub-domains individually).

To add a domain to the list of exclusions, please contact your account manager. They will add them in  "Admin.System.Emails.ThrottlingExcludedDomains"

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Email Throttling FAQ

1. Can email throttling be applied to individual mailings?
No, email throttling currently works on all mailings being sent out and not for a particular send. Once enabled, any mailings sent from your Vuture instance will use the email throttling setting. However you can exclude certain domains from throttling, e.g. your own internal email domains where you may have already allowed Vuture emails to be accepted by your email server.

2. Is there a specific threshold (e.g. # contacts in one mailing) where Email Throttling should be enabled?
We recommend email throttling being enabled if you have any lists which have a large percentage of contacts (10% or more) at the same firm.

3. Can the recommended throttling gap of 1 second be varied? 

Yes it can be varied. Increasing it will slow down the delivery of emails to a given domain and reduce the number of emails per hour received by that domain. For example, setting the value to 2 seconds would send up to 1,800 emails per hour to each domain. For certain domains this may be higher than the threshold at which emails are dropped so you may need to vary the value to get best results.

4. How exactly does throttling work?

Throttling works by keeping a record in your Vuture database of the last time an email was sent to each domain and then checking this time stamp for each individual email as it is sent. If the time is less than the throttling gap then that email is delayed by the size of the throttling gap. This allows throttling to work even if you have multiple sends going on at the same time since the last send time for each domain is held centrally.

For example:

• You have a throttling gap of 1 second and are sending an email to 100 people @firmA.com - the first email is sent and the last send timestamp updated for firmA.com.
• The second email to @firmA.com checks the timestamp adds on 1 second and sets the second email to be sent - the last send timestamp is updated with this new time.
• By the end of the send, the last send time stamp for @firmA.com may be a couple minutes in the future - if any other mailings go out to @companyA.com before that time is reached, they will automatically look at the time stamp and be delayed so that every email to @firmA.com has a 1 second gap.