Connect any tool to Postfaro (generic SMTP settings)

Use this guide for any application that can send email through an SMTP server: CRMs, ERPs, newsletter tools, website plugins, scripts and so on. If we have a dedicated guide for your tool, use that instead:

Before you start

You need:

A finished Postfaro setup. Your customer panel shows the status Ready, and you received the “Your sending domain is ready” email.
A sender address created in the panel under Sender addresses — for example [email protected] or [email protected].
That address’s SMTP username and password. The password is shown only once, when you create the address. If you lost it, create a new password for that address in the panel (the old one stops working).

The settings

Setting	Value
SMTP server (host)	`smtp.postfaro.com` [PLACEHOLDER — final host name to be confirmed]
Port	587 with STARTTLS (recommended) — or 465 with SSL/TLS
Encryption	STARTTLS on port 587 · SSL/TLS on port 465 · never “None”
Authentication	Yes (LOGIN or PLAIN)
Username	The SMTP username shown in the panel for this sender address (it starts with `pf_`)
Password	The SMTP password for this sender address
From address	Exactly the sender address the credentials belong to
From name	Anything you like, for example “Acme Newsletter”
Reply-To	Optional. If you leave it out, replies go to the sender address and we forward them to the mailbox you set in the panel

Tip — which port? Use 587 unless your tool only offers “SSL” or your network blocks 587. Some tools label STARTTLS as “TLS”. If one combination fails, try 465 with SSL/TLS.

Important rules

One credential = one From address. Each sender address has its own username and password, and it can only send with that address in the From field. If your tool sends with a different From address, the message is rejected with an error like 550 sender address does not match [CONFIRM EXACT TEXT]. Create another sender address in the panel if you need one.

Send only bulk and campaign email through Postfaro. Postfaro spreads large sends over several days (up to 5,000 emails per day per account) and paces delivery per mailbox provider. That is ideal for newsletters and campaigns, but not for email that must arrive right now — password resets, order confirmations, invoices, two-factor codes, or your everyday correspondence. Keep those on your existing mail server. If your tool can only use one SMTP server for everything, read the trade-off in the Vtiger guide — it applies to any tool.

Your daily limit is shared. All sender addresses on your account share one daily cap. See How the daily cap and queue work.

Add an unsubscribe link. We automatically add a one-click unsubscribe header that Gmail, Yahoo, Outlook and others show as an “Unsubscribe” button. You should still include a visible unsubscribe link in the body of every marketing email, as most anti-spam laws require.

Test it

Send one message from your tool to an address you can check — ideally a Gmail and an Outlook.com mailbox.
In the received message, open “Show original” (Gmail) or “View message source” (Outlook) and check that SPF, DKIM and DMARC all show PASS.
Reply to the message and check that the reply arrives in the forwarding mailbox you set for that sender address.
In the Postfaro panel, the message appears under Activity [VERIFY PANEL LABEL].

During warm-up, your daily limit is lower; a test message counts toward it.

Troubleshooting

Symptom	Likely cause and fix
“Authentication failed” / `535`	Wrong username or password. Copy them again from the panel, or create a new password. Make sure you use the username (starting with `pf_`), not the email address [CONFIRM]. If your account is paused for non-payment, logins are also refused.
`550` … sender / From does not match	The From address in your tool is not the sender address these credentials belong to. Set the From address exactly (check spelling and domain).
Connection timed out	Your network or hosting provider blocks outgoing port 587 or 465. Try the other port, or ask your provider/IT to allow outgoing SMTP to `smtp.postfaro.com`.
TLS / certificate error	Choose STARTTLS for 587 or SSL/TLS for 465. Make sure the host name is exactly `smtp.postfaro.com` (not an IP address). Very old software may not support modern TLS.
`451` temporary error	Your account is paused (for example after a high bounce rate) or our system is briefly busy. Your tool will usually retry. Check the panel and your email for a pause notice.
Messages accepted but not arriving	They may be in the queue (daily cap or warm-up), or the address may be on your cancelled-addresses list. Check Queue and Cancelled addresses in the panel.