The bounce rate is a ratio showing the proportion of emails that were not delivered to their recipient compared with the total number of emails sent.

You must keep your bounce rate below 5% and your complaint rate below 0,05% to avoid any account deactivation.

Be very careful from now on to avoid any further bounces or complaints in the coming weeks so that you are not blocked from sending.

Suggested actions:

• Clean your mailing list(s) to remove invalid/non-existent and ultimately bouncing addresses. Sparrow has an email validation service available both in the control panel and via the API that can be used for this process.
• Only send to subscribers who have opted in with double opt-in.
• Implement CAPTCHA on all sign-up forms.
• Check whether your subscribers' email addresses are 6 months old or more. It is worth asking subscribers to reconfirm their interest through periodic confirmation emails and, in turn, removing inactive subscribers aged 6 months or more from your lists.
• Assess whether subscribers engage with your emails. Opens and clicks prove that subscribers are active and want your content. As above, you will want to remove inactive subscribers unless they reconfirm their interest through a periodic confirmation email.
• Make sure emails have a clear unsubscribe link and honour unsubscribes promptly.
• Find out how to build a strong email reputation in our FAQ.