How do I implement an X-header or body tag to help identify my mail?

X-250ok-CID header:

By adding a header to your email campaign, you can assist Inbox in uniquely identifying your campaign. Simply include an additional header named X-250ok-CID with a unique value for each campaign.

X-250ok-CID body tag:

For users who don’t have the ability to inject a header into outgoing email, we offer the ability to embed a tag in the HTML body of your email. Simply include, anywhere in the body, a tag that looks like this:

<!--X-250ok-CID: uniqueid1234567890-->

Some best practices for creating a unique value for your header include:

  • Do not include any spaces in the value
  • All X-250ok-CID values should be unique PER CAMPAIGN
  • Prefix your campaign value with a company name or nickname
  • Consider including a timestamp in your value to help ensure uniqueness

If you include this header with your campaigns, you will be able to query our API with it, and it will be displayed throughout the Inbox reports. Child accounts inherit x-headers from their parent account so feel free to contact 250ok to have your parent account configured to accept the header types below.

For new parent accounts and their associated child accounts, (Note: This does not apply to some older parent accounts) 250ok will look for the following header types by default:

  • X-250ok-CID
  • X-rpcampaign
  • X-PVIQ
  • X-Campaign-ID
  • X-CampaignID
  • x-job

250ok can also accept the following x-header types.

  • Tag-id
  • X-10pl8ID
  • X-Campaign
  • X-Campaign_ID
  • x-cid
  • X-eC-messenger-mid
  • X-EMarSys-Identify
  • x-jobid
  • X-Listid
  • X-MailingID

Open your 250ok Settings Menu and select “Contact Support” under Help Center or contact 250ok Support to configure your Inbox account.



BriteVerify email verification ensures that an email address actually exists in real-time


The #1 global data quality tool used by thousands of Salesforce admins


Insights and deliverability guidance from the only all-in-one email marketing solution

GridBuddy Cloud

Transform how you interact with your data through the versatility of grids.

Return Path

World-class deliverability applications to optimize email marketing programs

Trust Assessments

A revolutionary new solution for assessing Salesforce data quality


Validity for Email

Increase inbox placement and maximize subscriber reach with clean and actionable data

Validity for Data Management

Simplify data management with solutions that improve data quality and increase CRM adoption

Validity for Sales Productivity

Give your sales team back hours per day with tools designed to increase productivity and mitigate pipeline risks in real-time