When you add a lead from LinkedIn using the lemlist Chrome extension, you can attach any custom value to their contact record before pushing them to a campaign. That value becomes a variable you can place anywhere in your email — the subject line, the opening, the body, or the end.
By the end of this tutorial, you'll know how to create a custom contact field, fill it in while adding leads from LinkedIn, and use it as a variable in your campaign emails.
Why this matters
Most email personalization stops at first name and company. Custom contact fields let you go further: capture anything you notice while browsing a lead's profile — a pain point their posts reveal, a recent hire, a product they just launched — and inject it directly into your email copy. The main template stays the same; the part that matters changes per person.
Before you start
You should already have the lemlist Chrome extension installed.
You should already have a campaign created, or know which campaign you want to add leads to.
You should already be adding leads from LinkedIn into lemlist.
How it works
You’ll complete this setup in 4 phases:
Create a custom field for your personalized value
Fill in that field while adding the lead from LinkedIn
Push the lead into your campaign
Use the custom field as a variable in your email template
Phase 1: Create a custom field for the personalized value
Open a lead in LinkedIn and expand the lemlist Chrome extension panel on the right side.
In the General tab, go to the Contact fields section and click the + button to create a new field. This lets you store a custom value for each lead directly from the extension.
Enter a field name such as last sentence, keep the field type as Text, then create the field. A text field is best here because you want to write a short custom sentence for each contact.
Phase 2: Fill in the custom value for the lead
Once the field is created, scroll through the contact fields in the extension until you find it.
In your new field, type the sentence you want to use for this specific lead. This value will be saved on the contact and can later be inserted into your email with a variable.
Phase 3: Push the lead to your campaign
After filling in the custom field, click Add to campaign, then choose the campaign where you want to send the email. This ensures the lead enters the right workflow with the personalized sentence attached to their contact record.
You can confirm the value was saved by opening your campaign’s lead list and checking the custom column. You should see your personalized sentence in the field for that lead.
Phase 4: Use the custom field in your email
Open your campaign sequence and go to the email step.
In the email body, insert your custom variable where you want the personalized line to appear. If your field is named last sentence, the variable will appear as
{{lastSentence}}Place it at the end of the email if you want it to act as a custom closing line. This keeps the main email reusable while letting the final sentence change per lead.
Use the preview to make sure the variable renders correctly for the lead. You should see the actual personalized sentence instead of the variable name.
Example
Here are three different ways you might use a custom field, depending on what you notice while browsing a lead's LinkedIn profile:
Hey {{firstName}},
{{personalNote}}
[Rest of your email]
Best,
[Your name]Lead just posted about a challenge they're facing → write that into the field:
Noticed you've been posting about the difficulty of keeping SDR ramp times under 60 days — that's exactly what we help with.
Lead's company recently hit a milestone → reference it directly:
Congrats on the Series B — that kind of growth usually means the support team is about to get stretched thin.
Lead switched roles recently → acknowledge the transition: ``` I saw you moved into the Head of RevOps role earlier this year — curious what your first big priority has been. ``` Same template, same send process. The only difference is the one line you wrote while you were on their profile.
Best practices
Keep the sentence short and natural.
Reference something specific from the person’s profile, post, company, or role.
Use the same custom field across campaigns if you want a consistent workflow.
Preview before launching so you can confirm the variable is rendering correctly.
Troubleshooting
Issue: The custom field does not appear in the extension.
Cause: The field may not have been created yet or the extension needs to refresh.
Fix: Create the field from the + button in contact fields, then refresh the panel or reopen the lead.
Issue: The email shows {{lastSentence}}
Cause: The variable name may not match the field, or the field is empty for that lead.
Fix: Check the exact variable name in the email step and confirm the custom field has a value in the lead list.
Issue: The lead was added to the campaign, but the sentence is blank.
Cause: The field may not have been filled in before pushing the contact.
Fix: Update the contact record with the sentence and verify the campaign uses the correct variable.
Tip: This works best when your main email stays mostly standardized and your custom field is used for one highly relevant closing sentence. It’s fast to personalize and easy to scale.