Why do my emails getting out so slowly? There are many factors that you need to consider when you are sending high volume emails and below are few general factors:
i) Email size
The size of the e-mail is based on the amount of data and slows the delivery of email if your size of e-mail is large. For instance, the content of your e-mail attachments or graphics like photos. We may suggest that you use connections to web server records.
ii) Invalid email addresses
If there are many bounce backs e-mails because subscribers are rejecting invalid e-mails, which is not double opt-in email addresses, then the e-mail queue will be created and eventually slow down the delivery speed
The use of an anti-virus program can occasionally affect the email delivery speed, as each message takes a few seconds before it is sent out.
iv) Transmission speed
It will also affect your email sending experience if your Internet connection speed is slow.