Understand mailbox management best practices, daily sending velocity, automated deliverability warmup, and custom DNS authentication in SkySenders Outreach.
To safeguard domain reputation and maintain high inbox placement:
Recommended Volume: Send 30–40 cold outreach emails per mailbox per day (default setting is 30 emails/day).
Aggressive Threshold: Never exceed 50 emails/day per mailbox, even on mature, warmed-up accounts.
Minimum Time Gap: SkySenders enforces a default minimum time gap of 5 minutes between consecutive dispatches from the same mailbox to emulate authentic human behavior.
Scaling Capacity: To send 500 emails/day, connect 15–20 mailboxes spread across multiple secondary domains rather than over-saturating a single mailbox.
Domain-Diverse Rotation: When assigning multiple mailboxes to a campaign, SkySenders groups mailboxes by root domain and alternates domains sequentially. This guarantees that consecutive emails are sent from different domains, preventing ESP rate-limiting spikes.
Match ESP Contact (Smart Matching): When enabled, SkySenders detects the recipient's email provider. Leads with Google-hosted inboxes are automatically matched to your Google Workspace mailboxes, and leads with Microsoft-hosted inboxes are routed through your Microsoft 365 mailboxes, maximizing native delivery.
Warmup should never be treated as a one-time setup step. In cold outreach, your inboxes experience natural fluctuations in open rates and spam reports. Keeping automated peer-to-peer warmup active (generating positive opens, star marks, and 30%–50% reply engagement) counterbalances cold volume and prevents abrupt reputation drops.
Every sending domain must have the following DNS records configured with your domain registrar:
SPF: TXT record authorizing sending servers (e.g. v=spf1 include:_spf.google.com ~all).
DKIM: CNAME or TXT public key signing outgoing message headers.
DMARC: TXT record at _dmarc.yourdomain.com enforcing alignment policies (e.g. v=DMARC1; p=quarantine;).
Custom Tracking Domain: CNAME record at the domain level pointing your chosen subdomain (e.g. cdn or track) to cdn.sys-gateway.com to brand open and click tracking links.
Mailbox Disconnection: If an OAuth session is revoked or SMTP credentials fail, SkySenders flags the mailbox as DISCONNECTED, suspends dispatches from it, and alerts you in the dashboard.
Bounce Rate Auto-Pause: If campaign bounce rates cross your safety threshold (e.g. 5%), SkySenders automatically pauses the campaign to prevent blacklisting. You can inspect the bounce view to identify invalid addresses before resuming.
