Outreach Tips9 min read
Avoiding Spam Filters: Technical and Content Best Practices
Technical and content strategies to ensure your cold emails reach the inbox.
NobleProxy Team
Proxy Experts
Beating Spam Filters
Spam filters evaluate technical setup and content. Master both.
TL;DR: Authenticate properly (SPF/DKIM/DMARC), warm IPs, avoid spam triggers, and write like a human. Technical foundation matters as much as content.
Technical Requirements
Email Authentication
- SPF: Add TXT record authorizing sending IPs
- DKIM: Add TXT record with public key
- DMARC: Policy for handling failures
Sending Infrastructure
- Clean IP reputation
- Proper warmup
- Consistent sending patterns
- Static residential proxy support
Domain Health
- Aged domain (3+ months ideal)
- Not on blacklists
- Proper DNS records
- Good sending history
Content Guidelines
Subject Lines
Avoid:
- ALL CAPS
- Excessive punctuation!!!
- Spam triggers (FREE, ACT NOW)
- Clickbait
Use:
- Conversational tone
- Personalization
- Under 50 characters
- Accurate preview
Body Content
Avoid:
- Heavy HTML/images
- Multiple links
- Attachments
- Spam trigger words
Use:
- Plain text (or minimal HTML)
- 50-150 words
- Single CTA
- Conversational tone
Spam Trigger Words
Common filters for:
- FREE, GUARANTEED
- ACT NOW, LIMITED TIME
- $$$ or excessive numbers
- "Dear Sir/Madam"
- Unsubscribe links in first email
Testing Before Sending
Tools to check spam score:
- mail-tester.com
- GlockApps
- Litmus
Test with different email providers (Gmail, Outlook, Yahoo).
Proxy Role
Clean IPs from NobleProxy help establish trusted sending infrastructure from the start.
spam filtersdeliverabilityinbox
Written by NobleProxy Team
Proxy Experts
The NobleProxy team helps businesses scale their cold outreach with reliable static residential proxies. We share our expertise to help you succeed.