SMTP Relay & Mail Server Hosting in Romania

Mailboxes and transactional mail, kept apart

These are two flows with different risks. Your team's mailboxes live on Mailu, with webmail, spam and virus filtering, quotas and IMAP access. The mail your application generates, such as invoices, password resets and notifications, leaves through another channel with its own IP and reputation. That way an abused web form does not block your business correspondence, and a badly timed campaign cannot damage the mailboxes your staff work from.

• Mailu installed on your domain: webmail, IMAP, filters, quotas
• A separate relay for messages sent by the application
• Authentication per application user, with sending limits
• Monitoring of queues and of rejected messages

Best practices we apply to deliverability

Deliverability is not luck, it is a checklist. We apply it at installation and revisit it regularly, because the rules of the large mailbox providers change from year to year without notice. What follows is what we configure and what we write into the guide you receive, together with the DNS values published for your domain and a note on how to read the reports that arrive.

• SPF, DKIM and DMARC published correctly, with aggregate reports switched on
• PTR and reverse DNS matching the server name, plus gradual IP warm-up
• Mandatory TLS in transit, with MTA-STS for domains that support it
• Separate reputation for mailboxes and for the transactional relay
• Sending limits and bounce handling, with list clean-up

Port 25, DNS and what stays with you

Many teams in Romania discover that port 25 is blocked on home networks and at several internet providers, as an anti-spam measure. That is why applications send on port 587 with authentication, and 25 stays for server-to-server traffic only. We publish the required DNS records ourselves, including MX, SPF, DKIM and DMARC, and explain what to watch in the reports. The full guide, with sending examples, is linked from this page.

Included hours and migration

Installing Mailu, configuring the relay and migrating mailboxes come out of your monthly hours: 1–8 h on VPS, 5–10 h on dedicated servers depending on the plan, 10 h on GPU servers. Request the work in the client panel under DevOps Services and propose the migration window, usually a weekend. Moving from another provider is free. Hours do not roll over, and anything above the quota is accepted and billed separately.

How we work

1. Request it in the panel

   Tell us how many mailboxes you have, where they live today and what your application sends, then propose a migration window under DevOps Services.

2. We scope the work

   We check the domain, the current DNS and the IP reputation, then agree what moves first and how long the sending warm-up will take.

3. We build it and test delivery

   We install Mailu and the relay, publish the DNS records, migrate the mailboxes, then test delivery to the major mailbox providers.

4. Handover with the guide

   You receive the configuration guide, the published DNS values, sending examples for your application and a walkthrough of the DMARC reports.

Use cases

Technology stack

• Mailu
• Postfix
• Dovecot
• Rspamd
• ClamAV
• Roundcube
• Let's Encrypt
• Prometheus

Frequently asked questions

• What is an SMTP relay and how does it work?

  It is a server that accepts the messages your application sends and delivers them onward to recipients, handling queues, retries and reputation. The application authenticates and submits on port 587, and the relay adds the DKIM signature and manages rejected mail.

• Why is port 25 blocked, and which SMTP port should I use?

  Port 25 is blocked on many residential networks to stop infected machines sending spam directly. Applications should submit on 587 with STARTTLS, or 465 for implicit TLS. Port 25 is for server-to-server delivery only. We configure and document all of this.

• Do I need an SMTP relay if I run my own mail server?

  Often yes. A relay with a clean, well-warmed IP keeps application mail from sharing a reputation with your staff mailboxes. It also gives you queues, rate limits and bounce handling, which a plain mailbox server does not manage well.

• How do I set up SPF, DKIM and DMARC for my domain?

  We publish them in DNS for you. SPF lists the sources allowed to send for the domain, DKIM signs messages cryptographically, and DMARC says what happens to failures and sends you reports. We start in monitoring mode and tighten the policy once the reports look clean.

• Self-hosted Mailu or Google Workspace?

  Google Workspace is simple, but your mail and its metadata sit with a US-headquartered provider and you pay per mailbox. Mailu on your own server gives you control, EU data and a mailbox count limited only by resources, in exchange for operations that we take over inside your included hours.

• What happens to my mail archive during migration?

  We move it in full over IMAP, checking message counts and folder structure. We pick the window with you, usually a weekend, and keep the old source active until you confirm that everything is where it should be.