Scaling an Email Program
While Maintaining Delivery

A B2B AI company had just taken on a much larger contact list and wanted to start emailing it regularly. With a smaller list and no one dedicated to managing HubSpot, they had sent only about 1,500 marketing emails in the previous five months.

Sending a lot more email to a new list is risky. New lists usually contain bad addresses from people who changed jobs, made typos, or entered fake emails to get past a form.

Emails to those addresses bounce back undeliverable, and too many bounces make Gmail and Outlook treat the sender like a spammer. Once that happens, even people who want your emails stop seeing them. The program needed a clean, trusted foundation before it could scale.

1. Authenticate the sender

   I set up SPF, DKIM, and DMARC: three checks that prove to inbox providers an email really comes from the company.

2. Prepare the contact list

   I imported the list, matched each column to the right field, removed duplicates, and grouped contacts so each campaign reached the right people.

3. Test the full path

   Before every send, I tested the full path myself, from email to form to HubSpot record.

4. Clean before increasing volume

   When the first sends turned up bad addresses, I cleaned them out before increasing volume.

Program scale

72,952

marketing emails sent

~1,500 →

Calculated baseline for the preceding 152 days, compared with 72,952 sends.

Send volume · January 1–June 1, 2026

From January 1 to June 1, 2026, the program sent 72,952 marketing emails. The approximately 1,500-send baseline is calculated from HubSpot’s reported 4,872.87% increase over the previous 152 days, not a directly observed count.

Send-volume report

Delivery after initial cleanup

99.31%

delivery rate

Hard bounces

0.19%

Unsubscribes

0.19%

Spam reports

0%

Delivery metrics · February 1–June 1, 2026

After the first month’s cleanup, the February 1–June 1 report showed 99.31% delivery, 0.19% hard bounces, 0.19% unsubscribes, and 0% spam reports. The unsubscribe rate was 75.56% lower than in the previous 121 days. These figures do not measure inbox placement.

Delivery report

The reports cover different periods. Delivery and reported complaint metrics do not establish inbox placement.

I created a sunset rule to remove unengaged contacts from regular sends.

Tools

HubSpot (email, segments, reporting)

Skills

Email deliverability; email authentication (SPF, DKIM, DMARC); data import and hygiene; segmentation; marketing automation; QA testing.

Contribution credit: My consulting partner owned strategy and copy. I owned HubSpot email operations, including authentication setup, imports, list hygiene, segmentation, and QA.