This article is designed to help prevent you avoid bounced emails and give a broad overview of the bounce messages you may receive.
Understanding Bounce Messages
There are two types of bounces and a few reasons why they would occur:
*1) Prospects have encountered a hard bounce (seen as a 5.x.x error). Below are some common reasons this could happen:
- Recipient email address does not exist i.e. you have an incorrect email address
- Domain name does not exist
- Recipient email server has completely blocked delivery. Please see the attached spam best practices guide
*2) The email has encountered a soft bounce (seen as a 4.x.x error). Below are common reasons you would see a soft bounce occur:
- Recipient Mailbox is full (over quota)
- Email message is too small
- Email message is too large
- Your emails are image-only
- Your emails use red-flagged words like "order status", "Desperate", "Double your income", "Invoice", "Sign-up free today", and "Online Pharmacy", etc.
- You didn't authenticate your sending domain
- You can authenticate your sending domain in the following ways:
- SPF - Adds the IP addresses allowed to send email via your domain name in your DNS record
- DKIM - Also based on the DNS record, this authentication solution is used to sign emails with a public or private key system
- DMARC- This new technology allows the sender to check whether emails have been properly authenticated by the ISP or webmail
*NOTE: Endpoint protection services (e.g. Symantec & McAfee) may block Outreach emails from being delivered to prospects. In this case, we would recommend enabling our Branded URLs feature within your Outreach account.
What can I do to prevent bounces?
The advice we typically give is to use a service to verify the emails you're are trying to send to. Email Hunter and Rapportive are free and work fairly well. DiscoverOrg and Datanyze are not free, but they are very effective. Kickbox.io is another good resource for verifying large lists.
We also advise that you target a much smaller audience at companies instead of targeting everybody with an email address. For instance, our sales team is only allowed to contact 5 people at a company at any given time. Basically, if you are sending the same 100 emails to the same companies servers in a day, there is a high chance that server will block you. Bulk email by definition is spam, so If you are sending a similar copy to a lot of recipients at the same company, their mailing servers are more likely to pick up on it.
Outreach has a few ways that we can help. We have domain level throttling, which allows you to set the max number of emails one domain can be sent per 24 hours. We also have sequence throttling, which a lot of people overlook, but this is something that can not only help your workflow but also improve deliverability over the long run. Another thing here might be to limit the number of exact date and time sequences your users are running. The intervals of an interval sequence would help email deliverability as your emails would be spread out over a defined schedule of time, and not all delivered at the same time to your prospects. Lastly, as a final safety measure, if a large number of e-mails all bounce during a short time period, Outreach will temporarily lock your mailbox for 24 hours. This is to help ensure that your e-mail domain's reputation score is protected, as bounced e-mails can damage the reputation for your entire organization and mean that all of your e-mails are more likely to be flagged as Spam.
As far as domain monitoring, we recommend MXtoolbox. They can provide comprehensive blacklist checks and domain health reports.
Attached is a guide on spam best practices; we recommend that you take a quick look so that all of the hard work you put into writing emails lands in the inboxes of your prospects.