7 Flodesk Mistakes That Hurt Your Email Deliverability (and How to Fix Them)

Your emails are written. Your Flodesk design is gorgeous. And somehow a quarter of your list is finding it in the promotions tab, or the spam folder, wondering why they ever signed up.

Deliverability is the unglamorous part of email. It’s also the part that decides whether anyone sees your beautiful design. The good news is that most problems come from a handful of fixable mistakes.

Here are seven Flodesk mistakes that can hurt your email deliverability, based on Flodesk’s own guidance, and what to do about each one.

Related: 9 Reasons Why Flodesk Is the Best Email Marketing Platform in 2026

What Is Email Deliverability?

Deliverability is where your email lands after it’s been delivered: inbox, promotions or spam.

Flodesk explains the difference neatly in its guide to improving deliverability. Delivery means the recipient’s mail server accepted your email. Deliverability is where it ends up afterwards. You can have a high delivery rate and still have deliverability problems if people never see your emails.

Inbox providers like Google, Yahoo and Outlook ask a few questions about every sender: is this sender trustworthy, do people want these emails and are recipients engaging or ignoring them? Everything below comes back to those questions.

7 Flodesk Mistakes That Hurt Your Deliverability

Each mistake below sends inbox providers a signal that your emails might not be wanted.

1. You Haven’t Authenticated Your Domain

Domain authentication proves your emails are really coming from you. Flodesk says that in 2026 it’s no longer optional, and it covers three things: DKIM (verifies the email wasn’t altered), SPF (confirms which servers can send on your behalf) and DMARC (tells inbox providers what to do if something looks suspicious).

The fix: add your custom domain email under Account settings, then Email setup, and authenticate it under Domain setup. Unauthenticated emails are more likely to be filtered or rejected.

2. You’re Sending From a Free Email Address

Sending from an address like you@gmail.com, you@yahoo.com or you@hotmail.com is a common spammer behaviour, according to Flodesk. It can send messages to spam, get emails blocked or damage your sender reputation.

The fix: use a custom domain address that you own, like hello@yourblog.com. If you’re switching, don’t do it overnight: tell your engaged subscribers first, ask them to add the new address to their contacts, then send your first emails from the new domain to engaged subscribers only and build up gradually.

3. You Keep Emailing Subscribers Who Never Engage

Repeatedly emailing large groups with no recent activity is a major red flag for inbox providers. Flodesk says that sending to fewer engaged subscribers is often healthier than sending to a much larger, disengaged audience.

The fix: create a segment of subscribers with no recent activity (30 to 60 days is a common starting point, and Flodesk says 6+ months is likely disengaged for most lists), exclude them from regular sends and continue emailing your most engaged people first. Excluding isn’t unsubscribing, and you can reintroduce them gradually. My guide to Flodesk segments shows you how.

Related: How to use Flodesk Segments to Increase Your Email Open Rate

4. You Send Inconsistently

Inbox providers prefer predictable behaviour. Flodesk recommends sending at least once a month (weekly or biweekly is even better), avoiding sudden spikes in volume and not emailing your whole list after a long pause.

The fix: pick a rhythm you can keep. If you haven’t emailed for a while, start with small, engaged segments and increase gradually. Flodesk says even gaps of 4 to 6 weeks may need a gradual warm-up.

Need subject lines that get opened? Grab my free Email Subject Lines to Boost Your Open Rates and write something worth opening.

5. Your Subject Lines and Content Are Misleading or Image-Only

Content still matters, especially while you’re rebuilding trust. Flodesk’s advice is to avoid misleading subject lines, use clear and honest language, don’t rely on images alone and always add alt text to images. It also says to avoid link shorteners, and to use full URLs.

The fix: write a subject line that matches the email, keep real text in your emails and use full links.

Related: 5 Email Subject Line Formulas That Get Your Newsletters Actually Opened

6. You Ignore Replies

Replies are one of the strongest engagement signals inbox providers see, even though Flodesk can’t track them. If someone replies, they’re highly engaged, so add them to a warm or highly engaged segment and keep emailing them.

The fix: ask a question in your emails, invite people to hit reply and read what comes back.

7. You Have Unclear Permission

Flodesk lists purchased or scraped email lists, and emailing people without clear, explicit consent, among the things that damage sender reputation. It also lists clear permission and expectations as a sign of a healthy list: subscribers knowingly opted in and understand what they’ll receive.

The fix: only email people who signed up, and tell them what to expect when they do. A good welcome sequence does exactly that.

Related: The 3-Email Welcome Sequence That Turns New Subscribers Into Readers And Buyers

A smaller list that reads your emails beats a bigger one that ignores them.

A Note on Open Rates

Don’t judge deliverability by open rates alone.

Apple Mail, Gmail and others’ privacy protections mean opens and clicks aren’t always tracked, and some people read emails without triggering any activity. Flodesk says deliverability today is about reducing risk signals, not identifying every perfectly engaged reader. Look at patterns over time instead: replies, purchases, bookings and people telling you they love your emails.

My roundup of 10 email marketing mistakes to avoid covers the wider picture.

A Quick Deliverability Checklist

Run through this list once a month.

Key Takeaways

• The biggest Flodesk mistakes are about trust: authenticate your domain and send from a custom domain address.
• Send to engaged subscribers first, and exclude people with no recent activity rather than deleting them.
• Send consistently and welcome replies.
• Keep subject lines honest and emails readable even if images don’t load.

Email deliverability isn’t a mystery, and it isn’t a hack. It’s a handful of boring habits done consistently. Avoid these Flodesk mistakes, fix the foundations first and your beautiful emails will have a much better chance of being seen. 🌶️