Zylar bloghttps://zylar.io/blogField notes on cold email: deliverability, infrastructure, sequences. How to recover a burned cold email domainhttps://zylar.io/blog/burned-domain-recoveryhttps://zylar.io/blog/burned-domain-recoveryTue, 13 Oct 2026 09:00:00 GMTDeliverabilityTo recover a burned cold email domain, stop sending, check blocklists and Postmaster Tools, fix the root cause and ramp slowly, or retire the domain. Running cold email for 20 clients without losing trackhttps://zylar.io/blog/cold-email-agency-operationshttps://zylar.io/blog/cold-email-agency-operationsTue, 13 Oct 2026 09:00:00 GMTAgenciesTo run cold email for 20 clients, give each a workspace, name domains and inboxes consistently, keep an infrastructure ledger and report weekly. What cold email really costs in 2026: inboxes, domains and toolshttps://zylar.io/blog/cold-email-cost-breakdownhttps://zylar.io/blog/cold-email-cost-breakdownTue, 13 Oct 2026 09:00:00 GMTStrategyReal 2026 cold email costs by inbox type: Google $2–3/inbox, Outlook $0.30–0.40, SMTP $0.50–0.99. A 100k/month stack runs about $360 in inboxes. Cold email infrastructure: the complete setup checklist (and what to automate)https://zylar.io/blog/cold-email-infrastructure-checklisthttps://zylar.io/blog/cold-email-infrastructure-checklistTue, 13 Oct 2026 09:00:00 GMTInfrastructureThe cold email infrastructure checklist: domains, redirects, inboxes, SPF/DKIM/DMARC, tracking, warm-up, rotation, monitoring, and which steps to automate. Why cold email lands in Outlook junk (and how to fix it)https://zylar.io/blog/cold-email-outlook-junkhttps://zylar.io/blog/cold-email-outlook-junkTue, 13 Oct 2026 09:00:00 GMTDeliverabilityCold email lands in Outlook junk because of failed authentication, bulk-style signals and tenant filters. Fix DMARC alignment, links, volume and test placement. Email warm-up for cold email: what it does, and why yours isn't workinghttps://zylar.io/blog/email-warm-up-guidehttps://zylar.io/blog/email-warm-up-guideTue, 13 Oct 2026 09:00:00 GMTDeliverabilityEmail warm-up builds sending history for new inboxes, but can't fix bad lists, broken auth or spammy copy. Warm-up times by inbox type, and what to check first. Gmail, Yahoo and Microsoft bulk sender rules: what cold emailers must do in 2026https://zylar.io/blog/gmail-yahoo-microsoft-bulk-sender-ruleshttps://zylar.io/blog/gmail-yahoo-microsoft-bulk-sender-rulesTue, 13 Oct 2026 09:00:00 GMTDeliverabilityGmail, Yahoo and Microsoft require bulk senders to use SPF, DKIM, aligned DMARC, one-click unsubscribe and keep spam under 0.3%. What cold email must do. How many domains and inboxes do you need for cold email?https://zylar.io/blog/how-many-inboxes-cold-emailhttps://zylar.io/blog/how-many-inboxes-cold-emailTue, 13 Oct 2026 09:00:00 GMTInfrastructureInboxes needed = daily sends ÷ the per-inbox rate for your inbox type (Google 15–20, Outlook 3–10, SMTP 11–14). 150k a month takes about 770 inboxes on 59 domains. Instant domain swap: replace a burned cold email domain without losing a sendhttps://zylar.io/blog/instant-domain-swaphttps://zylar.io/blog/instant-domain-swapTue, 13 Oct 2026 09:00:00 GMTInfrastructureWhen a cold email domain burns, the fix usually costs days of lost sends and manual inbox shuffling. Here's the manual process, and how an instant domain swap removes it. How to set up SPF, DKIM and DMARC for cold emailhttps://zylar.io/blog/spf-dkim-dmarc-cold-emailhttps://zylar.io/blog/spf-dkim-dmarc-cold-emailTue, 13 Oct 2026 09:00:00 GMTDeliverabilitySet up SPF, DKIM and DMARC for cold email with one SPF record under 10 lookups, 2048-bit DKIM, and DMARC at p=none with reports before quarantine. The 3-step cold email sequence we'd send tomorrowhttps://zylar.io/blog/three-step-cold-email-sequencehttps://zylar.io/blog/three-step-cold-email-sequenceTue, 13 Oct 2026 09:00:00 GMTCopyA 3-step cold email sequence template: a short intro with one ask, a value-adding follow-up in the same thread, and a polite last touch, plus timing and subject lines.