Category
Business Email
18 articles
Migrate a client's mailboxes without losing a message
Agency runbook to move a client's mailboxes to a new provider: inventory, TTL, two-pass imapsync, MX cutover and count-based verification.
Move client domains to DMARC p=reject, in stages
Take each client domain from p=none to p=reject without losing mail: sender inventory from rua reports, alignment, subdomains, a rollout calendar and a client message.
Exim and Dovecot: check that your package is truly patched
Exim 4.97 can be patched while the upstream fix is 4.100.1. Read the package changelog, test your exposure, restart the daemon, and check the logs.
Roundcube 1.7.5 and 1.6.20: patch 20 webmail flaws
Roundcube 1.7.5 and 1.6.20 fix 20 flaws. Inventory the versions across client accounts, update by branch and check that the fix is really in place.
DMARCbis RFC 9989: what changes for your mail server
RFC 9989, 9990 and 9991 replaced RFC 7489 in May 2026. Learn the three concrete changes — np tag, removal of pct, Tree Walk DNS — and how to update your DNS records and
Self-hosted email server on VPS: 2026 comparison
Stalwart, Mailcow or Postfix+Dovecot: compare RAM, complexity and spam filtering scope to choose the right email server for your VPS in under 10 minutes.
Postal: self-hosted SMTP platform for agencies
Deploy Postal on a VPS to manage transactional and marketing email across your client portfolio: web UI, queues, bounce tracking and per-server stats.
AWS WorkMail EOL: migrate to self-hosted Mailcow on VPS
AWS WorkMail shuts down on March 31, 2027. Full guide: S3 export, IMAP migration with imapsync and DNS cutover to self-hosted Mailcow.
Migrating from Mailchimp to self-hosted Mautic on VPS
Export your Mailchimp lists, import them into self-hosted Mautic on a VPS and configure SPF, DKIM and DMARC before your first send. Complete guide.
DMARC p=quarantine: stop sending in monitor-only mode
In 2026, Google and Microsoft throttle senders of more than 100 emails/day stuck on DMARC p=none. SPF, DKIM, DMARC and List-Unsubscribe one-click checklist.
Email deliverability on VPS: port 25, cold IP and PTR
Port 25 blocked by the provider, fresh IP flagged as spam, missing PTR: the three structural blockers to resolve before your first send from a VPS.
Stalwart Mail Server: SMTP, IMAP and JMAP in a single Rust binary
Deploy Stalwart Mail Server on a VPS: full email server in Rust, native SPF/DKIM/DMARC, single binary without a complex multi-container Docker stack.
Hosting Stalwart Mail Server on a VPS: Complete Guide
Install Stalwart Mail Server on a VPS: a single Go binary for SMTP, IMAP, JMAP and native multi-tenancy to manage multiple client domains without Docker.
Postfix SMTP Relay on VPS: Client Transactional Emails
Set up Postfix as an SMTP relay on a ServOrbit VPS: dedicated IPv4, SPF, DKIM and DMARC aligned for your entire cPanel client portfolio in under an hour.
Hosting Your Own Email Server on a VPS with Mailcow
Deploy Mailcow on a Linux VPS to run your own sovereign email server: installation, deliverability and migration from Google Workspace.
Migrating professional email: leaving Gmail and Microsoft 365
Microsoft 365 raised prices in 2026 and EWS shuts down in October. Here's how to migrate your business email without interruption.
BIMI: display your logo in Gmail and Apple Mail
BIMI displays your brand logo next to your emails in Gmail, Apple Mail and Yahoo. Full guide: DMARC requirements, VMC, CMC and DNS record.
SPF, DKIM, DMARC: passing the 5,000-email threshold
Gmail and Outlook reject senders without aligned SPF, DKIM and DMARC with an SMTP 550 error. Here is how to configure all three records.