A five-point checklist for sending an email campaign
In short: Before you hit send, check five things: your sender domain's reputation, its status, whether it is blacklisted, whether it is authenticated, and your campaign's content. Zoho Campaigns' anti-spam system won't send a campaign that has problems in the message or the sender domain, so running this checklist first saves you time.
At Zoho Campaigns, we've built an efficient anti-spam system that validates every aspect of a campaign before sending it. This system won't send a campaign under the following circumstances:
- When there are issues with the email message
- When there are issues with the sender domain
- When there are issues with both the email message and the sender domain
Since our system will send the campaign only after the issues are resolved, we've created a checklist for you to run through so you know your campaign is ready before hitting the send button. Let's take a look at it.
Sender domain reputation
The reputation of your sender domain will definitely impact the performance of your campaigns. If your sender domain has a positive reputation, email deliverability will be good. If your sender domain has a negative reputation, deliverability will be poor and you won't hit your conversion goals. We recommend you use a sender domain that has earned a positive reputation from mailbox providers and anti-spam services to send your campaigns. Google asks senders to keep their spam rate below 0.10% and never reach 0.30%, and Yahoo recommends staying below 0.3% as well.
If most of your contacts use Gmail, you can use Google Postmaster Tools to understand how Gmail treats your sender domain. Google has retired the Domain and IP Reputation dashboards, so after you configure the tool, check the Spam rate and Compliance status dashboards instead.
Sender domain status
We urge our users to use a business domain sender address and ensure that your website is up and running. If your website is down, and if the mailbox provider's anti-spam system identifies this, they may classify your emails as spam.
Blocklist status
When you use a blocklisted sender domain to send emails, email deliverability will take a serious hit and the emails you send may land in the spam folder. To prevent this from happening, you must ensure that the sender domain isn't blocklisted. After checking the reputation of your sender domain, you can use tools and anti-spam services such as MXToolbox, Spamhaus, SpamCop, or others to check if the sender domain is blocklisted. Not every list matters equally; see things to know about blocklists.
If your sender domain has been blocklisted, you need to submit a delist request to the anti-spam service that blocklisted your sender domain. Find and fix the cause first, or you may be listed again; see how to handle a blocklisted sender domain or IP address.
Sender domain authentication
After verifying the status and reputation of your sender domain, you must ensure that your sender domain is authenticated. Major mailbox providers consider the authentication status of a sender domain when making inbox decisions. If you use an unauthenticated sender domain to send emails, mailbox providers may deny inbox placement for your emails.
At Zoho Campaigns, we strongly urge our users to authenticate their domain before sending emails. The most commonly implemented domain authentication mechanisms are SPF, DKIM, and DMARC. If you send 5,000 or more emails a day, all three are required: Gmail and Yahoo (since February 2024) and Outlook.com (since May 5, 2025) can reject or junk email that doesn't meet the requirements.
Campaign content
Now that you've validated your sender domain, you can start focusing on your campaign's content. The performance of your campaign hugely depends on the content you offer. Here's what you should do before hitting the send button:
Check for spam phrases
Our anti-spam system will scan your campaign's content for phrases that are commonly found in spam emails. If a campaign contains spam phrases, our anti-spam system won't approve the campaign. Instead, we'll inform the user about the phrases and will approve the campaign only after those phrases are removed from the email message. See why emails land in the spam folder.
Verify the URLs used in your content
We urge our users to be careful about using URLs in email content. Avoid the following URL types in your email message:
Blocklisted URLs and URLs that lead to blocklisted websites
When there are blocklisted URLs in your email content, or URLs that take email recipients to blocklisted domains, your emails may get classified as spam. Mailbox providers may even blocklist your sender domain if your emails have these URLs. When a domain is blocklisted, the URLs associated with the domain will also get blocklisted. So, we urge you not to use URLs associated with a blocklisted domain in the email message.
Broken URLs
Broken URLs are those that don't work. When email recipients click a broken URL, they will see a 404 Error page. When the receiving servers of mailbox providers find broken URLs in an email message, they mark the email as spam.
Shortened URLs and URLs with multiple redirects
Spammers mostly use shortened URLs and URLs with multiple redirects to perform malicious activities. When the receiving servers of mailbox providers find these in the emails they receive, they might consider the emails to be suspicious and may deny inbox placement. So, if you craft a campaign with even one of the URLs, our anti-spam system won't approve it. We recommend using legitimate URLs that take recipients directly to the target website.
Verify the images used in your campaign
While scanning a campaign's content, our anti-spam engine will look for pornographic and sensitive images, spoofed images and logos of famous brands, or spoofed web pages of other businesses. If the system finds any of these in a campaign, the campaign will not be approved. So, we urge our users to be careful about the images that they use in their campaign.
Check the merge tags
When crafting personalized campaigns, use merge tags offered by Zoho Campaigns and ensure that they are configured properly. If you're downloading templates from third-party services, the merge tags associated with those templates will not work. We urge our users to remove such merge tags before using the templates in their campaigns. After crafting a campaign, you can send your campaign to test accounts so that you can identify faulty merge tags and correct them. See seven tips to foolproof your campaign.
To enjoy a hassle-free email sending experience, we recommend you maintain quality mailing lists, choose the right set of contacts to send your emails, and adopt hygienic email sending practices.