Automated Email Campaigns with Gmail API

Step 01

Problem

Manual email campaigns are slow, inconsistent and don't scale. Sending personalized follow-ups to dozens of contacts takes hours and it's easy to lose track of who received what.

Step 02

Context and constraints

I built a complete automated email marketing pipeline using the Gmail API for multi-touch campaigns with AI personalization, Google Sheets status tracking and daily rate limiting.

Role: Full pipeline developer: Gmail API integration, multi-touch campaign orchestration, DeepSeek personalization, Sheets tracking and rate control.

Step 03

Key decisions

• Gmail API with persistent OAuth: no dependency on paid email marketing services.
• DeepSeek generates each campaign touch with a different angle (intro, value, sector insight, closing).
• Google Sheets as contact database: each row = one contact with status, current touch and date.
• 5 touches per contact with randomized spacing (+4d, +6d, +7d, +7d) for natural pacing.
• Configurable daily limit (25/day) with randomized send spacing (2-5s) to avoid blocks.

Step 04

Outcomes

• Fully automated 5-touch campaigns with zero manual intervention.
• AI personalization with different approach in each touch.
• Real-time contact status tracking in Google Sheets.

Metrics

• 25 sends/day with randomized 2-5s spacing.
• 5 touches per contact with 4-7 day gaps.
• DeepSeek personalization for each campaign touchpoint.

Step 05

Learnings and next improvement

Step 06

Visual resources