What are the safe sending limits for cold email?

Conservative limits (community consensus):

Google Workspace:

• Per inbox daily: 15-20 emails
• Warmup period: 28-35 days
• Ramp schedule:
  • Week 1: 5/day
  • Week 2: 10/day
  • Week 3: 15/day
  • Week 4: 20/day

Microsoft 365:

• Per inbox daily: 10-15 emails
• Warmup period: 35-42 days
• Ramp schedule:
  • Week 1: 3/day
  • Week 2: 5/day
  • Week 3: 10/day
  • Week 4-5: 15/day

Safety rules:

• Never exceed 25/day per inbox regardless of warmup
• Use ESP matching (Google to Google, MS to MS)
• Plain text only, no images in first email
• No links in first email
• Use custom tracking domain

Example setup for 200 emails/day:

• 10 Google inboxes × 15/day = 150
• 5 Microsoft inboxes × 10/day = 50
• Total: 200/day