1 Hash Busting: Avoid adding random characters in the mail subject or mail content to fool email spam filters. Eg: "W.in p.r!z.e"
2 Deceptive Subject Lines: Don't start the email subject with "FW: / RE: / Urgent – / Thanks for your order!" to think an ongoing communication with the sender.
3 From Email ID and Name: It is recommended that the "From Email ID" and the "SMTP Username/Email ID" and "reply-to" must be same. Use your full name in the "Email Name" field. The email ID should be "yourname@", "contact@", "support@", "sales@".Not like "342Johnd@domain.com", "firstname.lastname@example.org".
4 Email Content: Avoid the use of large or unusual fonts, or more than one font, background colours, many bold or italic HTML tags in your mail content. Make sure you use the HTML tags wisely in the email content and it should not look like an advertisement or a brochure.
5 Spam Words: Avoid using email risky/spam words such as "free", "limited offer", "click now", "congratulations", "dear friend", "amazing", "special promotion", "guarantee", "cancel at any time", "increase sales", "order now", "promise you", "this is not spam" etc.. Also, avoid using lot of capitalized letters & excessive punctuations in email subject or content. Exclamation marks are mostly risky in email subject lines.
6 Image Text: Don't compose a text message in an image to fool spam filters.
7 Use of Links: Make sure that you only link to legitimate websites with reputable domains.
8 Image-to-text Ratio: Maintain image-to-text ratio. We recommend maintain a ratio of 80% text to 20% images in your email.
9 Email Size: Don’t go crazy with email size (30 KB is just fine).
10 HTML Mail: We have tested that plain text versus branded emails and found that the branded emails actually get higher engagement. The HTML male should be mobile responsive. Use compressed images. The message should be 600-800 pixels. This will make the message look good in most mail clients.
11 Email Signature: It is recommended that you should add email signature and Physical Address in the footer section of your email.
12 Unsubscribe Link: Adding a list-unsubscribe header in the mail header is a kind of guarantee that you are a legitimate sender. Also, add the unsubscribe button in the message content to improve the experience for your customers.
13 Never Buy Email Lists from Others: Because the mailing lists may contain lots of invalid or dead emails.
14 Clean Up Your Mailing list: Use an email verifier tool to clean up your contact emails.
15 Dedicated IP: If you are on a shared IP, it is recommended to buy a dedicated SMTP server/ IP. Because others also use the shared IP and it may have gotten your IP blacklisted for spam.
16 Follow IP Warm-up: IP warming is a gradual process that happens over time to establish a reputation as a legitimate email sender in the eyes of ISPs (Internet Service Providers).
17 Whitelist Your IP: Unfortunately, if your IP got blacklisted in some spam filters then you should request the spam filter providers to whitelist your IP.
18 DNS Records: Update the SPF, DKIM, and DMARC records on your DNS to avoid email spam and bounce.
19 Hourly Email Sending Limit: Ask your email service provider or check the daily and hourly email sending limit.
20 Stay in Touch: Maintain a steady flow of communication.