To find out more about what Bounces are and why they are a problem, see Bounce Limits
Bounces are ultimately caused by old or mis-typed email addresses so reducing the bounce rate involves a combination of trying to ensure emails are captured reliably and performing regular housekeeping on lists to remove any emails which no longer work and not retaining contacts for longer than is reasonable.
In most cases, a smaller high-quality list is preferable to a large low-quality one
Improving email address capture
Depending on how you have obtained the email addresses, you should consider whether there is a high chance that people can deliberately or accidentally mis-type their addresses to something that will either bounce or will risk having someone else mark the unsolicited email as SPAM.
Don't use third-party contact lists
Third-party email contact lists should not be used and in most cases are likely to be unlawful.
Avoid businesses selling you "legitimate" marketing data
Companies that provide contact data for businesses are currently working in a grey-area of the GDPR, in many cases using "Legitimate Interests" but you should be careful that these could be shut down at short notice if the relevant Authority decides that their usage is not proportionate or expected by the Data Subject. There is also a higher chance of invalid email addresses being targetted.
Use double-opt in to verify email addresses before using them
The ideal scenario is that you have a double opt-in, which would involve sending an email to the entered email address for people to "verify" their email. There are also other techniques like double-entering the email or showing a message to show the email address entered and asking the user to verify that they typed it correctly.
Obtain email addresses in an unambiguous way
You should also avoid trying to obtain email addresses in a non-obvious way, which is more likely to lead to incorrect email addresses. In most cases, you should be very obvious with your usage of email addresses and giving people the chance to opt-out if it is not required for your business function. If someone doesn't want marketing emails, why try and send them any?
Would the recipient have provided a false email address?
If you are collecting emails using any kind of survey or data collection then consider whether the recipient has a reason to enter a valid email address. Many people are weary of companies who are too quick to send them information that they might not want and seeing "Please enter your email address" is likely to cause people to enter invalid ones, especially if you make the field mandatory but don't need it. If you are offering a reason to sign up e.g. "enter a prize draw", then you must still allow people to opt-out later.
Do not use fake email addresses
Do not use fake email addresses e.g. as a workaround for a SmartSurvey tool that doesn't seem to do what you want or to test tooling. Not only might it cause a bounce to be registered against your account but if the fake email happens to be someone else's real email, you might receive an "abuse report"
Avoid large contact lists and use other channels
Take special care with very large lists (> 2000 contacts) when the chance of old data is much greater. You could e.g. regularly send out an email asking people to re opt-in to a mailing list, allowing you to naturally prune old/invalid email addresses or otherwise use other channels to augment the reach of any marketing-type surveys. Sending out links on Social Media, for example or via QR codes on printed material, might be a way to get responses without directly targetting people and where bounces are simply not an issue.
Use lists regularly to get regular bounce information
Also with large lists, you should be using them regularly enough (via any of your email providers) to be able to manage bounces as they happen. If you e.g. don't use the list for 12 months or longer, there is a much higher chance of getting high numbers of bounces, even if the emails were obtained legitimately in the first place. You might also split the contact lists up into specific target groups, which might make it easier to send out regular content or emails to re opt-in to existing mail lists.
Housekeeping of contact lists
Don't keep data any longer than necessary
Many organisations have distribution lists stored in a number of places both internally and externally, but GDPR in the UK and EU requires you by law to maintain these lists, to allow a quick and easy opt-out of any non-essential contact. Although this might seem like a conflict with the nature of business reaching as many people as possible, sending people information they don't want doesn't help business. Instead, high quality content, relevant that people want, sent at a reasonable frequency is what will help you to gain loyal customers.
Monitor bounces and update contact lists
Email addresses can become invalid soon after they are captured, although in most cases, it will simply continue to happen slowly over time. You should use all of the systems that you have, including SmartSurvey, to monitor any bounced emails and update your contact lists accordingly to make sure that none of your systems are sending to bounced addresses.
Exporting delivery information in SmartSurvey
In SmartSurvey, you can do this by exporting an invitation to Excel which will include the various pieces of delivery data including whether the recipient has clicked to opt-out and whether the message was delivered. By filtering on these columns, you can update your own contact lists to remove these people before sending more invitations. To export the data, simply go into the "View Results" section of your invitation and click the "Export Data" button under "Actions":
Opt-out links should work
You should make sure that your own opt-out links work correctly. SmartSurvey provides an opt-out link in every invitation that is sent out but this can only work against a single contact list. Ideally, you should allow opt-outs across all of your systems where possible using an opt-out link that directly updates your main internal contact list. This allows people to remove themselves from lists before they stop using an email address, which can reduce future bounces.
If you are a service-provider using SmartSurvey on behalf of your customers, make sure that your customers also manage their contacts correctly since your account will be blocked if they don't do this.