Help CenterCampaign ManagementBest PracticesWhy Mailmodo Blocks Accounts with High Bounce Rates

Why Mailmodo Blocks Accounts with High Bounce Rates

Last updated December 14, 2023

Mailmodo ensures reliable and efficient email delivery, but accounts may be blocked in certain situations due to a high bounce rate. This article explains why and how users can address and prevent these issues.

What is a bounce rate?

A bounce rate is the percentage of emails sent that are not delivered to the recipient's inbox. Bounces can be temporary (soft bounces) or permanent (hard bounces).

Learn more about  bounce rate  and how to reduce it.

Why does Mailmodo block accounts with high bounce rates?

1. Negative Impact on Deliverability and Reputation:

A high bounce rate indicates that a significant portion of emails sent from an account are being rejected by recipient mail servers. This could be due to invalid email addresses, full mailboxes, or spam filters. When a high number of bounces occur, it raises concerns for Mailmodo as an email service provider.

ISPs (Internet Service Providers) monitor email deliverability and reputation closely. If they detect a pattern of high bounce rates from Mailmodo's IP addresses, they may blacklist those addresses to protect their users from spam and potential security threats. This blacklisting can significantly hinder the delivery of emails for all Mailmodo users, not just the ones with high bounce rates.

2. Maintaining a Healthy Email Ecosystem:

Mailmodo strives to maintain a healthy email ecosystem where emails are delivered efficiently and reliably. High bounce rates disrupt this ecosystem by increasing the risk of spam filtering, blacklisting, and ultimately, poor deliverability for all users.

By blocking accounts with high bounce rates, Mailmodo encourages senders to adopt responsible email practices, such as maintaining clean email lists, verifying email addresses, and avoiding sending unsolicited emails. This helps to protect Mailmodo's reputation and ensures that its IP addresses remain in good standing with ISPs.

In summary, Mailmodo blocks accounts with high bounce rates to safeguard its overall email deliverability, protect its reputation, and maintain a healthy email ecosystem for all users.

When does Mailmodo block the account?

a. The senders associated with Mailmodo SMTP gets blocked whenever the bounce rate at any point of time touches 5%. We also send a warning message if bounce rate touches 3%

b. The number of emails sent under considerations are all the emails sent in an account through the senders setup on Mailmodo SMTP. So, if you have 3 senders set up on Mailmodo SMTP sending 3 campaigns in parallel, senders will be blocked if there is 5% bounce for the overall emails sent in an hour from that account.

c. This is the reason sender ids get blocked even if on campaign dashboard bounce rate for the overall campaign is less than 5%


Note: If a customer uses Mailmodo SMTP to send email from Mailmodo platform along with other platform like clevertap, moengage etc, all the emails will be considered for bounce analysis.

Frequently Asked Questions

Does bounce in above analysis involves soft bounce or hard bounce?

We check both hard bounce and soft bounce. If hard bounce touches 5% or soft bounce touches 5%, the condition will be met and sender id will be blocked.

What happens once block condition is met?

If the block condition for a sender domain on Mailmodo SMTP is met we block all the domains/senders configured on Mailmodo SMTP for that account. We do not do anything with non-Mailmodo SMTPs in that account. Even if a domain, say, is set both on Mailmodo SMTP and non-Mailmodo SMTP we only block the Mailmodo one.

What happens to current running journeys, triggered campaigns and bulk campaigns post blocking?

a. Bulk Campaigns → Since sender id is blocked the bulk campaigns are aborted. A notification for the same is sent in the notification section on Mailmodo app.

b. Trigger campaigns → We do not abort triggered campaigns or journey campaigns. However, emails will start failing for those campaigns.

How and when to unblock?

Users must complete a form specifying the nature of their campaigns and outlining the steps they intend to take to clean their email. Subsequently, our team thoroughly evaluates the submitted responses and unlocks the domain.

What if there is repeat block of the same domain?

Our team decides whether to unblock a sender based on the situation. If it's a genuine case, like sending to the wrong list, we unblock the domain after a final warning. But if there's a risk of spam or cold emailing, the domain stays blocked.

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