By default, Remindax sends your expiration reminders from [email protected]. If you would prefer your recipients to see your own address, you can connect your own SMTP server.

Once connected, reminder emails are sent through your mail server and arrive from your address — so they look like they came from you, and their deliverability is backed by your own domain reputation.

What this changes (and what it doesn't)

  • Expiration reminder emails — sent from your address
  • Billing and invoice emails — sent from Remindax
  • Account emails (sign-up, password reset, 2FA) — sent from Remindax
  • Support ticket emails — sent from Remindax
  • Weekly report emails — sent from Remindax

Only expiration reminders move to your server. Everything else continues to come from Remindax, so you will still receive account and billing mail normally even if your mail server has a problem.

Before you start

You will need:

  • A paid plan. This feature is not available on free or trial accounts.
  • To be the account owner. Team members with settings access can view the configuration but cannot change it.
  • Your SMTP server details — host, port, encryption, username and password. Your email provider or IT administrator can supply these.

A note on authentication: Remindax connects using standard username-and-password authentication (AUTH LOGIN). OAuth, "Sign in with Google", and app-specific single sign-on are not supported. Gmail and Microsoft 365 both need extra setup — see Settings for common providers below.

Setting it up

Step 1 — Open the settings

Go to Settings > Email Sender.

Step 2 — Enter your server details
  • SMTP Host — your mail server's address, e.g. smtp.gmail.com or mail.yourcompany.com
  • Port — 587, 465, 25 or 2525 (see below)
  • Encryption — must match the port you chose
  • Username — usually your full email address
  • Password — your mailbox password, or an app password / API key
  • From Email — the address recipients will see, e.g. [email protected]
  • From Name — the name recipients will see, e.g. Acme Ltd. Leave blank to use the From Name set on each email template
  • Reply-To — optional. Where replies should go, if different from the From address

Choosing the right port and encryption — these must be paired correctly, or the connection will fail:

  • Port 587 with STARTTLS — the modern default. Try this first.
  • Port 465 with SSL/TLS — also common, especially on cPanel and shared hosting.
  • Port 2525 with STARTTLS — an alternative when 587 is blocked.
  • Port 25 with None or STARTTLS — often blocked by hosting providers. Avoid unless told otherwise.
Step 3 — Save

Click Save. Your password is encrypted before it is stored, and is never shown again — the field will be blank next time you visit the page. Leaving it blank when you save keeps the password you already entered.

Step 4 — Send a test email

Click Send test email. This is required — your SMTP server is not used for real reminders until a test succeeds. Until then, reminders keep going out from Remindax, so nothing is disrupted while you are setting things up.

If the test fails, the error from your mail server is shown on screen. See the Troubleshooting section below.

Step 5 — Turn it on

Switch on Use my SMTP server for reminder emails, then save.

The status badge at the top of the page should now read Connected. From the next scheduled reminder onwards, your emails will be sent from your address.

Understanding the status badge

  • Not verified — details are saved but no successful test yet. Reminders are still sent by Remindax.
  • Connected — working. Your reminders are being sent from your address.
  • Error — your server rejected recent messages. See "What happens if your mail server fails" below.
  • Disabled — turned off. Your details are kept so you can switch it back on later.

Settings for common providers

Values change from time to time — check your provider's current documentation if something does not work.

Gmail / Google Workspace
  • Host: smtp.gmail.com
  • Port / Encryption: 587 STARTTLS, or 465 SSL/TLS
  • Username: your full Gmail address
  • Password: an App Password, not your normal password

Google requires 2-Step Verification to be enabled on the account before you can create an App Password. Your everyday Google password will be rejected.

Gmail also applies daily sending limits (typically a few hundred messages a day for personal accounts, higher for Workspace). If you send a large number of reminders, use a dedicated sending service instead.

Microsoft 365 / Outlook
  • Host: smtp.office365.com
  • Port / Encryption: 587 STARTTLS
  • Username: your full email address
  • Password: your mailbox password

SMTP AUTH is switched off by default on Microsoft 365 mailboxes. An administrator must enable it for the specific mailbox before this will work. Some organisations disable it tenant-wide for security, in which case use a dedicated sending service instead.

Microsoft also throttles sending (commonly around 30 messages per minute).

cPanel / Plesk / shared or VPS hosting
  • Host: mail.yourdomain.com, or the server hostname your host gave you
  • Port / Encryption: 465 SSL/TLS, or 587 STARTTLS
  • Username: your full email address, e.g. [email protected]
  • Password: the mailbox password

The most common mistake here is entering only the part before the @ sign. These servers almost always require the complete address.

SendGrid
  • Host: smtp.sendgrid.net
  • Port / Encryption: 587 STARTTLS, or 465 SSL/TLS
  • Username: the literal word apikey
  • Password: your SendGrid API key

The username really is apikey — not your account email.

Mailgun
  • Host: smtp.mailgun.org
  • Port / Encryption: 587 STARTTLS
  • Username: the SMTP login shown in your Mailgun dashboard, e.g. [email protected]
  • Password: the SMTP password from that same screen
Amazon SES
  • Host: email-smtp.<region>.amazonaws.com
  • Port / Encryption: 587 STARTTLS, or 465 SSL/TLS
  • Username / Password: your SES SMTP credentials

SES SMTP credentials are generated specifically for SMTP and are not the same as your AWS access key and secret. Also check your account is out of the SES sandbox.

Zoho Mail
  • Host: smtp.zoho.com (or smtp.zoho.eu for EU accounts)
  • Port / Encryption: 465 SSL/TLS, or 587 STARTTLS
  • Username: your full Zoho address
  • Password: your mailbox password, or an app password if 2FA is enabled

Make sure your emails don't land in spam

This is the single most important step after connecting, and it is easy to overlook.

When you send from your own address, receiving mail servers check whether your domain actually authorises the server you are sending through. If it does not, your reminders may be marked as spam or rejected outright — even though Remindax sent them successfully.

Ask whoever manages your domain's DNS to confirm:

  • SPF — a DNS record listing the servers allowed to send mail for your domain. Your SMTP provider will tell you what to include.
  • DKIM — a cryptographic signature proving the message really came from your domain. Your provider supplies the key.
  • DMARC — optional but recommended. It tells receiving servers what to do when SPF or DKIM fails.

If you are using your own mail provider's SMTP server to send from an address on the same domain, this is usually already configured. Problems typically arise when the From address is on one domain and the SMTP server belongs to another.

Tip: after switching over, send a test email to an address at a different provider (a personal Gmail account, for example) and check it does not land in the spam folder.

Delivery tracking changes

Reminders sent through your own server are marked Sent in Remindax once your mail server accepts them.

They will not show as Delivered or Bounced. Those statuses come from Remindax's own mail infrastructure, which is no longer in the path once you connect your own server.

To see what happened after your server accepted a message — whether it was delivered, deferred or bounced — check your mail server's logs or your provider's dashboard.

If tracking delivery inside Remindax matters more to you than sending from your own address, leave this feature switched off.

What happens if your mail server fails

Remindax does not quietly resend failed reminders from its own address. If your server is unavailable, the reminder is not sent from [email protected] behind your back.

Instead:

  • The reminder is marked as a send error in your reminder history.
  • Remindax automatically tries again on the next hourly send, up to three times. Most short-lived problems — a brief outage, a rate limit, a network blip — resolve themselves this way, and the reminder is delivered a little late rather than not at all.
  • You receive an email alert telling you your SMTP server is failing, with the error your server returned.
  • If failures continue, Remindax switches your SMTP server off automatically and resumes sending reminders from [email protected]. This is a safety net so your reminders keep reaching your contacts while you investigate. The status badge changes to Error and your settings are kept.

Once you have fixed the problem, send a test email again to reactivate your server.

Reminders that had already failed permanently at that point are not re-sent. Check your reminder history for anything marked as a send error during the outage.

Troubleshooting

535 Incorrect authentication data

Your server rejected the username or password. In order of likelihood:

  • Use your full email address as the username. [email protected], not reminders. This is the most common cause on cPanel, Plesk and most hosting providers.
  • Gmail — you must use an App Password, and 2-Step Verification must be enabled first.
  • Microsoft 365 — an administrator must enable SMTP AUTH for the mailbox.
  • SendGrid — the username is the literal word apikey.
  • Amazon SES — use SES SMTP credentials, not your AWS access key.
  • Retype the password. If your browser autofilled the password field with a saved password for a different site, the wrong value may have been stored. Click into the field, retype it, save, and test again.
Connection timed out / could not connect

Remindax could not reach your mail server at all.

  • Check the hostname for typos.
  • Try port 587 instead of 465, or vice versa (remember to change Encryption to match).
  • Confirm your mail server accepts connections from outside your own network. Some servers only allow their own hosting customers to connect.
  • If your provider requires IP allow-listing, ask them to allow Remindax's sending server.
TLS or SSL handshake errors

Almost always a port and encryption mismatch. Use 465 with SSL/TLS, or 587 with STARTTLS. Swapping those two is the usual cause.

Also check that your server's TLS certificate is valid and not expired.

The test email succeeds, but reminders still come from Remindax

Check all of the following:

  • The toggle Use my SMTP server for reminder emails is switched on and saved.
  • The status badge reads Connected, not Not verified, Error or Disabled.
  • Your plan is a paid plan and has not expired.
  • Email reminders are enabled under Settings > Services.

Also remember the change applies to reminders sent from that point onwards. Reminders already sent are not affected.

The test email succeeds, but recipients never receive reminders

Your server accepted the message but something downstream stopped it.

  • Check the recipient's spam folder.
  • Review the SPF and DKIM section above — this is by far the most common cause.
  • Check your mail server's logs for the message to see whether it was delivered, deferred or bounced.
  • Check whether you have hit a sending limit on your provider.
Emails arrive but the sender name looks wrong
  • From Name on this page overrides the From Name set on individual email templates. Leave it blank if you would rather each template control its own name.
  • Some mail clients show the address a message was authenticated as rather than the From address, particularly when SPF or DKIM do not align. Fixing your DNS records usually resolves this.
I hit "Please wait a few seconds before testing again"

Test sends are rate-limited to protect your mail server and prevent abuse. Wait a moment and try again.

I can't see the Email Sender tab
  • The feature requires a paid plan.
  • Only the account owner can see and change these settings. Team members cannot, even with settings permission.

Turning it off

Click Disable on the Email Sender page.

Reminder emails immediately go back to being sent from [email protected]. Your server details are kept, so you can switch back on later by sending a fresh test email — you will not need to re-enter your password.

Still stuck?

Contact Remindax support and include:

  • The exact error message shown after a failed test.
  • Your SMTP host, port and encryption setting (never send us your password).
  • Which provider your mailbox is with.

That is usually enough for us to identify the problem straight away. You can reach us at https://www.remindax.com/contact