A spam complaint in Zoho Campaigns is recorded when a recipient clicks the Mark as Spam or Report Junk button in their email client. Complaint reports are fed back to Zoho Campaigns via feedback loops with major mailbox providers. Contacts who complain are automatically added to the DNC list and excluded from all future sends.
Spam complaint rate is one of the most heavily weighted factors in sender reputation scoring. Keeping complaint rate below 0.1% is strongly recommended; above 0.3% will trigger reputation damage and likely blocklisting of your sending domain or IP. Gmail and Yahoo now actively enforce complaint thresholds.
Use double opt-in, send only to contacts who recognise your brand, match content to audience expectations, and provide a one-click unsubscribe that works immediately. Make the unsubscribe link prominent — a frustrated subscriber who cannot find the unsubscribe link will reach for the spam button instead.
Aaxonix is a certified Zoho implementation partner based in Pune. Architecture-first, no surprises.