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Email Deliverability

What Causes High Email Bounce Rates?

If you’re like many of our customers, you struggle with high email bounce rates and may assume the problem is bad data — specifically inaccurate email addresses. The truth is, more often than not, the problem isn’t bad data. The problem is not following email best practices. Let’s explore what causes bounces and learn how to avoid them.

Hard Bounce (Permanent)
Invalid email address: address does not exist

Hard Bounce (Temporary Suspension)
Anti-SPAM block: got caught in the recipient’s SPAM filter for:

  • Non-compliance with CAN-SPAM or CASL regulations For example: email header or subject line was deceptive, irrelevant content, no unsubscribe option, etc.
  • Blacklisted or sender score/reputation below 70
  • Unauthenticated sender IP address; suggests possible security or other risk This may happen if you send from multiple email addresses and do not authenticate all, or send through a shared domain
  • Sending too many emails or sending them too often

Technical Bounce (Rare)
No response from the recipient server or returns other unrecognized error:

  • Indicates a technical issue somewhere along the path from sender to recipient; usually affects only a small percentage of the campaign and resolves quickly

Soft Bounce
Temporary block from the recipient’s server Example reasons: full inbox, message too long, server offline

To determine specifically what’s causing your emails to bounce, generate a report through your marketing automation platform and be sure to include the “cause” field and date timestamp. Then follow these best practices to help reduce your bounce rates.

Best Practices To Avoid High Bounce Rates

  • Authenticate all IP addresses and only send email from authenticated addresses.
  • Send only to reliable email addresses, such as those provided by InsideView. If unsure about the quality of an email list, InsideView can validate your emails for you.
  • Check your SenderScore
  • See if your email domain has been blacklisted at DNSStuff.
  • Mark addresses invalid and stop mailing to them, if they generate recurring bounces.
  • Comply with CAN-SPAM and CASL regulations to avoid SPAM filters.
    • Don’t use false or misleading sender addresses or subject lines.
    • Include an unsubscribe option (when sending within the U.S.) and honor unsubscribe requests promptly.
    • Use only opt-in addresses (when sending to Canada).
    • Only send messages that are relevant to the audience.
    • Monitor campaign volume and frequency. What’s acceptable will depend on your audience and content.

Email Deliverability and Insideview

InsideView offers a high degree of email accuracy — 80% (+/-5%) — and is rarely the cause of high bounce rates. All our emails are “Green,” meaning they’re safe to send. And we continuously validate our email addresses to maintain and improve that standard.

Our 3-Step Validation Process

Every 2 weeks, we validate all email addresses in our
database using a thorough 3-step process.

  • Check for malformed emails and valid domains.
  • Do a real-time username verification against the mail server.
  • Purge Red (invalid) and Yellow (questionable) addresses and hide unvalidated emails, which are emails that have been sourced between validation cycles.

Shades of “Green”

InsideView offers a high degree of email accuracy — 80% (+/-5%) —While all our email addresses are “Green,” it’s important to know there are two types of “Green” — “CatchAll” and “Non-CatchAll”. “CatchAll” is a server setting enabled by the recipient domain.

“Non-CatchAll” Green email addresses do not bounce and are 95% (+/-) deliverable. They have been tested against a non-CatchAll server that returns invalid email addresses, so they can be flagged and purged from our database. Emails that are “CatchAll” Green rarely bounce, because the server is set to receive all emails, but it may not deliver all. In other words, they use the CatchAll setting to manage SPAM internally.

Questions To Ask Yourself

  • Are you familiar with anti-SPAM laws (CAN-SPAM & CASL)?
  • Do you always provide an unsubscribe option?
  • Do you email to Canada? If so, has everyone on your list opted in? Note: No matter what other data providers promise, they cannot deliver “opt-in” lists, because recipients must opt in to receive emails specifically from you.
  • Are you careful to send only relevant messages and avoid misleading sender addresses and subject lines?
  • Have you authenticated all lP addresses you use to send emails?
  • Do you know your Sender Score?
  • Have you checked to see if your email address has been blacklisted?
  • Would you like to have the emails in your database validated?