An email queue consists of emails waiting to be sent by a server. It is an essential component of SMTP servers that creates a series of emails waiting to be processed for delivery. When you send a single email, the recipient can receive it and interact with it immediately, but when dealing with bulk or transactional emails, they won’t be sent all at once. This can also be a result of connectivity issues.
Email queues help to decouple the email production process from the consumption process and allow recipients to interact without being connected to the sender. Thus, the queued emails will await processing until the recipient is ready and available to receive them.
As an email marketer, you can send bulk emails simultaneously, especially with marketing automation, but your recipients will not receive them all at a time. This is done to enhance deliverability and prevent spamming, so the emails are queued and delivered step by step. SMTP servers start from the beginning of the queue when delivering the emails, so there is no fear of mixing it up.
What to do With a Clogged Email Queue
Email queuing has some benefits, and the SMTP server regulates it well; however, when emails remain in the queue for an abnormally long period, it can become a problem; the emails won’t bounce, they will eventually be sent, but the timing and deliverability can be altered.
The most common cause for clogged email queues is an exceeded volume of emails because some major mailbox providers enforce an email rate limit on each IP address. This limit is based on your sender’s reputation, so if you exceed this limit, you may queue up too many emails and get a clogged email queue. Therefore, ensure you stick to the limit of your mailbox provider so that your delivery will go smoothly.
In addition, if spam filters suspect your emails, you can get a clogged email queue. However, they will gradually allow your emails to be sent. In cases where the progress becomes too slow, you should unlist yourself and optimise your email campaign, or you will end up piling emails, which can even block your IP address from the spam filter.
Also, remember to check your device storage, the size of the email files, and your internet connection, as they can contribute to clogged email queues.