So you sent an email to one of the contacts listed on Winmo and it bounced! You know that because you just received a terse "Undeliverable" email in reply. What gives?! It means one of two possible things has happened. Read on for a quick primer of Hard Bounces vs. Soft Bounces.

Hard Bounces

The most straightforward scenario. A hard bounce occurs when the email address you are attempting to contact is simply incorrect. Look out for these common causes.

  1. The person's name is spelled incorrectly ( vs.
  2. The domain name is spelled incorrectly ( vs.
  3. There's an accidental space in the email address (john
  4. The email address once existed but no longer does (John Smith has moved on from and that email was deleted)

Soft Bounces

A common assumption anytime one receives a bounce is that it must be hard. But often it's not that simple. That's where soft bounces come into play. In these scenarios, the email is valid, but some other factor is to blame. Here are some common causes of soft bounces.

  1. The recipient's email inbox is full
  2. The email being sent is too long or has an attachment that is too large
  3. The recipient's email server is temporarily down
  4. The sender has been marked as spam

Best Practices

In addition to avoiding the pitfalls listed above that can result in soft bounces, keep the following best practices in mind to avoid the next worse scenario: the dreaded spam folder.

  1. Make sure your email isn't too long
  2. Don't use overly gimmicky subject lines (avoid exclamation points at all costs)
  3. Avoid sending too many messages over a short period of time

Next Steps

The easiest way to distinguish between a hard bounce and a soft bounce is to read the first few sentences of the bounce email. While many bounce templates quickly devolve into a string of techno mumbo-jumbo, the key is often in the first line. If you're really stumped, simply copy the code that corresponds to the bounce and Google it. The first page of results will tell you what you need to do.

Finally, what happens if it's a hard bounce from an email you pulled from Winmo? We want to hear about it! In those instances, simply submit a Email Verification ticket and we'll find the correct address for you. That can be done by toggling the Feeback button on the right side of any page on the website. See the example below.