Increasing volume in your email program usually involves:
- A temporary increase for a special event or a holiday.
- A permanent increase to reflect a new email stream, additional frequency, new email address acquisition sources or a company merger.
Mailbox providers are generally tolerant of volume increases as long as your sending reputation metrics do not exceed their internal thresholds related to spam filtering. Even low volume increases resulting in complaints, unknown users and spam traps can cause a poor sending reputation and deliverability problems. Mailbox providers are usually intolerant of unexpected large increases in volume as it may be interpreted as spam.
Best practices for increasing volume:
- Ensure the quality of your data. Use an email address validation service to ensure you are not introducing bad addresses into your list file. If your volume increase is associated with spam traps, complaints and unknown users, then it is more likely to cause deliverability problems. If you can’t implement real-time validation, then frequent batch validations are a good idea.
- Treat volume increases like an IP address warmup. Add volume incrementally over time. The more volume you have, the more time it should take.
- Respect the mailbox provider’s resources. Ensure your connection and throughput settings are set appropriately for each mailbox provider. Sudden increases in volume can be perceived as spam-like behavior, especially when you open too many connections to a mailbox provider’s server.
- SMTP bounce messages for signs of throttling and blocks.
- Deliverability and reputation (complaint rates, unknown users and spam traps) performance in Return Path Platform to see if you are encountering filtering as the volume is increased.
- Unsubscribe requests. Some of your subscribers may perceive unexpected and more frequent email as spam.
- Roll back or pause the volume increase if you see poor deliverability, an increase in throttling or block SMTP bounce messages, or an increase in complaints, unknown users, spam trap hits, and unsubscribe requests. Troubleshoot and fix the cause prior to resuming the volume increase or you may risk long-term negative effects to your performance.