What is Email Throttling and How to avoid it?

Email deliverability is one of the most important aspects of a successful email marketing plan. Your emails will not drive your recipients to take the action you want if they never make it to their inbox. Here we’ll dive deeper to know more about email throttling and discuss how to avoid it.

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What is Email Throttling?

When a recipient’s Internet Service Provider (ISP) limits the quantity of email they may accept from a sender for a set period, it is known as “Email Throttling.”

How Does It Work?

The Email Service Provider (ESP) delivers emails to many individuals during throttling, yet just for the initial few sends. The ISP blocks the following emails and does not deliver them, resulting in a soft bounce.

If recipient mailbox providers begin to reject or mark your emails as spam, this will affect the sender’s reputation. It will further affect the ability to deliver email effectively in the future. We must limit the emails to avoid this.

Why Does Email Throttling Occur?

Internet Service Provider (ISPs) typically limits the number of emails you can receive from a sender over a certain period. The ISP denies your delivery requests when you exceed the limit, which results in additional bounce-backs.

Certain factors may cause an ISP to reject email delivery, such as:

  • If your email is unsent to the intended recipient, the reason may be that the recipient’s mailbox is full.
  • The email database may contain invalid or dead addresses when the database is not maintained or cleaned regularly.
  • It could be that none of the server’s ports are open.
  • Sending an excessive number of emails from a new IP trying to build its reputation.
  • The receiving server’s failure to recognize your IP address or addresses leads it to consider your mail spam.

Methods to Avoid Email Throttling

1. Understand the ESP Limits

Follow the ESP’s boundaries to prevent email throttling. Before sending the email campaign, know more about the ESP’s limitations.

2. Warm up the IP

IP warming is the process of building a reputation for a new or inactive IP. Sending email from the new IP in small quantities at first and then progressively increasing it each day or week by a predetermined schedule is the warm-up procedure.

3. Boost your sender's reputation

Make full use of the IP address after warming up. Building a sender’s reputation is still in progress. There is significance in each email sent from this IP. The sender’s reputation will fall if a few emails end up in the spam folder. Therefore, we must boost the sender’s reputation to prevent this.

4. Scrub the email database

To keep the database clean, exclude all the invalid, dead, and unsubscribed emails from the list. It is one of the essential practices to follow to boost the reputation. Moreover, the scrubbed database may lower bounce-back rates and increase email deliverability.

5. Email segmentation and scheduling

Ensure you send the emails over a long period by scheduling them. Set a timeline for email throttles based on the selected limitations. One method is to filter emails based on domains. Separating the email database listings into many batches before delivering them is an alternative method. Use different IPs and domains for transactional and marketing emails. It will set their sending reputation apart.

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