Femke van der Berg

Femke leads the deliverability engineering practice at Blue Spirit Hosting. She joined in 2018 after seven years at Spotler (formerly Mailplus), where she ran the SMTP infrastructure and ISP relations function during the company's scaling from 200 million to 2 billion emails per month. Her core technical work covers PowerMTA virtual MTA topology design, multi-IP pool segmentation strategy, and the operational discipline of warming, rotating and decommissioning IPs across the Gmail-Outlook-Yahoo-iCloud quartet.

She is the architect of Blue Spirit's "engagement-first" warmup methodology, which replaces the traditional volume-curve approach with a relative-growth-rate model calibrated against per-ISP reputation signals. Across roughly 800 IP warmups since 2020, the methodology has reduced average time-to-full-volume from 42 days to 27 days for B2C senders and from 56 days to 34 days for cold-outbound B2B operators, while keeping spam complaint rates below 0.08% on Gmail Postmaster Tools throughout the ramp.

Femke contributed to the M3AAWG sender best practice document review process in 2022 and 2024, and has presented at the Dutch Email Marketing Association annual conference three times on topics ranging from BIMI implementation tradeoffs to the operational impact of Microsoft's May 2025 5,000-emails-per-day enforcement. She is fluent in Dutch, English, German and reads technical Spanish and French.

Outside work she races sailing dinghies on the IJsselmeer, reads paleography (medieval handwriting) for fun, and is slowly restoring a 1968 Citroën DS in her garage in Amsterdam-Noord.