SMS deliverability and carrier filtering

What gets filtered

• URL shorteners (bit.ly, tinyurl) — always use your own tracked domain.
• Cryptocurrency, gambling, CBD, firearms — restricted SHAFT verticals.
• All caps ("URGENT!!!").
• Too many emojis (4+).
• Public URLs that resolve to phishing or spam per carrier databases.

What signals good sender behaviour

• Steady volume, not sudden spikes.
• Low opt-out rate (< 2%).
• High reply rate (means your content is wanted).
• Registered brand and campaign.