4) Email Delivery schedule

Endeavor to keep to a scheduled time to send your email, avoid erratic broadcast. Permit to borrow this sentence from Neil Patel - not maintaining a regular schedule with your emails will create sending spikes.

5) Work on the credibility of your IP

I wish I can make this as simple as possible; systems recognize themselves via what is called an Internet protocol (IP), so your email is coming from an IP. If your IP is looking suspicious, the ISP will most like push your mail to the spam box. But you can gain credibility gradually.

Start your email campaign gradually, and then build it up. Start with email addresses of individuals you know will engage with your emails. Then you can start scaling it up

The moment the ISPs see that your emails are been opened, they will begin to deliver your mails in people's boxes and not spam or junk folders.

In conclusion, the higher the number of your emails that are delivered, the better your probability of getting good sales; avoiding practices like buying of email addresses and understanding that creating an email list is not a day’s job rather a gradual process is of good essence.