Sending tips

Read this guide before sending large volume of emails. By following these best practices you will increase your opening rate and avoid falling into spam.

Best practices for mail merge in Gmail

Mailmeteor send emails directly from your Gmail account and adds a sending delay between each email sent. These mechanisms prevent your emails from falling into spams compared to other email sending platforms. However, you have to abide by Google anti spam policies to maximize your email deliverability.

1) Warm-up your Gmail account

If your account is new, we recommend sending emails to a small list of recipients at first (less than 50 emails).

2) Stagger mass communications over several days

For large campaigns, try sending messages to one group of recipients, wait 24 hours, and then send to another group.

3) Make sure your contact list is clean

If your campaigns have a lot of bounced, Google will detect that your database is outdated or not legitimate. We strongly recommended you to keep your database as clean as possible. If we detect spamming behavior, we will have to block your account.

Google will temporarily reduce your quota if you meet one of these conditions:

  • 10 recipients in your campaign marked your email as spam

  • 10 emails fell into your recipients' spam folder

4) Review your email content and formatting

Look at the section below to check if your email can be considered as spam by filters.

Add unsubscribe links in your emails if you are running marketing campaigns.

How to avoid falling into spam?

First things first, spam are all unsolicited or undesired emails. To keep account safe and prevent spam, email providers have developed anti-spam filters. Knowing the best practices will help you avoid spam.

  • Your reputation is important: if your emails have been flagged as spams in the past, spam filters will flag your email address as spam. We recommend you to keep your sending clean so as not to harm your reputation.

  • Email content and formatting: spam filters can check email content to ensure it does not contain phishing or scam. Also, we recommend you to keep formatting as simple as possible, avoid uppercases, combination of fonts or colors, abusive use of exclamation marks.

  • Email headers (or metadata): these include the following fields: Date, From, To, and Subject of your email. Spam filters will check these fields to ensure there is nothing unusual there.

  • Structure of your email (HTML code): your email is made of the HTML language. Unstructured HTML code will be suspect to spam filters. Mailmeteor email editor is built on Gmail's native technology, that should clean your email format. However, we recommend you to create your email directly in the editor instead of copy pasting text from Word, Google Docs or using an HTML template.

If your email still ends up in spam, try the following:

  • Remove all links from your email

  • Remove any embedded images or logo

  • Remove formatting, use plain-text instead

  • Disable tracking before sending your emails

Increase your opening rate by personalizing email subject

When you are sending emails in bulk, it’s generally a good idea to personalize the email subject. It might certainly increase your open rate.

Mailmeteor lets you personalize your email subject

Check the following section to learn how to personalize email subject:

Spam laws vary from one country to another, you may check the applicable spam law in your country before sending campaigns.

Using Mailmeteor for automating emailing campaign is right and legal, but spamming is definitely not. We recommend you to abide by simple guidelines, such as the one established in the CAN-SPAM act.

What is CAN-SPAM?

CAN-SPAM is a law that establishes the rules for commercial email and messages, gives recipients the right to have a business stop emailing them, and outlines the penalties in case the law is violated. We cannot but recommend following these few rules.


  • Do include a valid physical business address in every email you send out

  • Do use clear "From," "To," and "Reply to" language that accurately reflects who you are.

  • Do provide a clear way to opt out of every email you send out, and honor the unsubscribe within 10 business days.


  • Don't sell or transfer any email addresses to another list.

  • Don't make it hard to unsubscribe from emails (avoid a paywall or several steps to unsubscribe)

  • Don't use deceptive subject lines in your emails