if you're sending all your cold email through Google Workspace only, or Outlook only, you're one filtering update away from your entire pipeline going dark.

i've seen this happen. repeatedly.

Google updates their spam filtering model. suddenly every Google-only sender sees open rates crater overnight. the people running a split between Google and Microsoft? they barely noticed. their Microsoft volume kept running while they adjusted on the Google side.

that's the Two-Lane Provider Strategy.

why you split

email providers update their filtering models independently. Google might tighten up one month, Microsoft the next. if 100% of your volume goes through one provider and that provider clamps down, you lose 100% of your sending capacity in one go.

splitting gives you resilience. when one lane gets turbulent, the other keeps your pipeline alive while you adjust.

the two configurations

70/30 split (recommended for most teams)

• 70% Google Workspace, 30% Microsoft/Outlook
• best when your ICP is primarily on Gmail/Google Workspace themselves
• Google inboxes tend to have better deliverability to other Google users

50/50 split (recommended for enterprise targeting)

• equal distribution between providers
• best when your ICP is a mix of corporate Outlook users and Gmail users
• gives you maximum resilience if either provider updates

decision template