FluentSMTP Alternative: When a Hosted Sending Service Makes Sense

Your Microsoft 365 connection in FluentSMTP failed again, and the log shows a 422 and not much else? The client secret ran out, and your site’s email stopped until someone noticed? Or you’re tired of being the person who looks after the sending account, the API keys and the DNS records behind it all?

You’ve got two ways out: four things to check when the Microsoft 365 connection fails, or, if you’re done looking after a sending provider, a FluentSMTP alternative that hands the job off, with the steps to switch cleanly.

A note before you read on: SendWP wrote this page, and we sell one of the options on it. Facts about FluentSMTP come from our own test install, from what its makers publish, and from its public support forum, with the date we read them. Last checked: 2026-10-15.

Is FluentSMTP still the right fit for you?

If you already run a good sending provider (or are happy to open one) and you’re comfortable with DNS records and API keys, FluentSMTP suits you. It’s free, it’s capable, and with Amazon SES behind it, sending about 3,000 emails a month costs you well under a dollar.

If you’d rather stop being your site’s email admin, with no provider account, keys or Microsoft Entra app to look after, a hosted sending service makes more sense. Read on either way, because the fixes come first.

What FluentSMTP already does well for you

Here’s what we saw in our test install and in its makers’ own description (FluentSMTP’s wordpress.org description and plugin code, read 2026-10-15):

• It’s free, with no paid tier. Its makers say it has no pro version and no premium add-ons, and we found nothing in its code locked behind a license.
• It offers 15 kinds of connection, including Amazon SES, Mailgun, Gmail or Google Workspace, Outlook or Office 365, and any SMTP server.
• It keeps an email log by default. Logs are kept for 14 days, and one setting stretches that to as long as two years.
• It can resend any logged email and retry failed ones. Resend worked in our test.
• It has a fallback connection. When your main connection fails, FluentSMTP tries a second one you’ve set up. It worked in our test.
• It alerts you when an email fails to send, on Telegram, Slack, Discord or Pushover. A daily check also flags a connection that has started failing.
• Sending costs very little. With Amazon SES, about 3,000 emails a month costs about $0.30 to $0.48 (Amazon SES pricing page, read 2026-10-15).

That’s a lot for a free plugin. What it doesn’t do is run the sending side for you. That part stays yours.

When the Microsoft 365 connection keeps breaking

Threads in FluentSMTP’s support forum (read 2026-10-15) include Microsoft 365 connections failing with a 422 error. If that’s what your log shows, start here.

Fix the 422 before you decide to switch

The 422 is FluentSMTP’s own label for a failed send, on every kind of connection, not Microsoft’s error. The words after it tell you the cause, and recent versions of FluentSMTP write Microsoft’s own reason there when Microsoft gives one.

Connecting Microsoft 365 means registering your own app in Microsoft Entra and pasting its client ID and secret into FluentSMTP. Here are the four things to check, from FluentSMTP’s forum and docs and Microsoft’s documentation (read 2026-10-15):

1. Send from a real mailbox, not an alias. Microsoft can refuse a From address the signed-in account has no right to send as.
2. Copy the client secret’s Value, and make a new one before it expires. Microsoft caps a secret at two years, and your site’s email stops when it runs out.
3. Make the redirect address in Entra match the App Callback URL FluentSMTP shows, exactly, capital letters included.
4. Update FluentSMTP, so the log shows Microsoft’s reason instead of a bare “Unauthorized”.

If one of those is your cause, fixing it gets your email going again. You could also point FluentSMTP at a provider like Amazon SES. That’s cheap, and still yours to run: FluentSMTP’s own guide has you verify your domain with DKIM records, request production access, and create an access key.

SendWP as a FluentSMTP alternative: what you hand off

With SendWP, you don’t connect a provider. SendWP sends the email. If you’d rather hand off sending, it’s the FluentSMTP alternative we’d suggest, because that’s the problem we built SendWP for.

• No provider of your own to run. No provider account, API keys or Microsoft Entra app to set up or renew. Your site’s email goes out through SendWP.
• Help with your domain’s DNS records. SendWP shows the SPF and DKIM records for your domain with a Copy button beside each, suggests a basic DMARC record, and rechecks your DNS when you ask.
• A 30-day email log in your SendWP account.
• A person to contact. SendWP has an email support team you can write to.

Where FluentSMTP is ahead: it costs far less in money, and its log can be kept longer. It also lets you set up a fallback connection, while SendWP has no second connection to configure. SendWP is a paid monthly service.

FluentSMTP and SendWP side by side

For one site sending about 3,000 emails a month, prices as of 2026-10-15:

On money, FluentSMTP with Amazon SES wins by a wide margin. What SendWP gives you instead is no provider to run.

Switch from FluentSMTP to SendWP in six steps

Your email keeps going out through FluentSMTP right up to step 3, so nothing changes while you set up. From the moment SendWP connects until you deactivate FluentSMTP, emails fail, so pick a quiet time and go straight from step 3 to step 4.

Before you start, note your From address in Settings > FluentSMTP. SendWP sends from a fallback address until your DNS records are in place and your From address is on your own domain, so it helps to know which address your site uses. If you don’t want the old log left in your database, open Email Logs and click Delete All Logs now.

1. Go to Plugins > Add Plugin, search for SendWP, then click Install Now and Activate. A red notice appears saying SendWP is “installed, but the service is currently disabled or disconnected on this site.”
2. Click Connect or register. in that notice, then Connect to SendWP.
3. Fill in the registration form, or click Login if you already have an account. Choose a plan when the plans page appears, then follow the prompts to finish connecting.
4. Straight away, go to Plugins > Installed Plugins and click Deactivate under FluentSMTP. You’ll see “Plugin deactivated.” and Settings > FluentSMTP leaves the sidebar.
5. In your SendWP account, open Domains, choose your site, then Deliverability. Before you add the SPF record: if your domain already has one, edit that record to include SendWP’s value instead of adding a second, because two SPF records break SPF. Add the DKIM record (a CNAME) and the SPF record at your DNS host, then click Recheck DNS.
6. Send a test: request a password reset from your site’s login screen. Then in your SendWP account open Domains, your site, Emails, and look for it in Email Logs.

That’s it. Two things to know about the plugin you just switched off.

Don’t leave FluentSMTP and SendWP both active

In our test, with both active and SendWP set up as connected, FluentSMTP’s log marked every email Failed with “Invalid address: (From): Array”. That’s why step 4 comes straight after connecting. If you see that, deactivate FluentSMTP.

What FluentSMTP leaves behind

Deactivating FluentSMTP, and even deleting it later, leaves its email log and its settings in your database. Once it’s off, nothing clears that log, and it holds recipients, subjects and message bodies, which is why we suggested Delete All Logs before step 4. If you put credentials in wp-config.php instead of the settings screen, remove those lines by hand.

Hand off your WordPress email and stop running a provider

You came here with a 422 that said next to nothing, a secret about to run out, or one provider dashboard too many. You can now check four things on a failing Microsoft 365 connection, or hand sending off to a FluentSMTP alternative and switch in six steps.

With SendWP there’s no Entra app or client secret to renew, and no provider account or keys to look after. SendWP shows your DNS records with a Copy button and rechecks them when you ask, and there’s a person to write to when something looks wrong. When you’re ready to hand it off, get started for $1 your first month.