Email marketing delivers the highest return on investment of any digital channel, but only if your messages actually reach the inbox in the first place.
Study after study shows email returns between 36 and 42 euros for every euro invested. But that number assumes the recipient actually sees the message. The problem is that spam filters are getting smarter, inbox competition is intensifying, and user attention is shrinking. The good news is that concrete techniques exist for improving deliverability, open rates, and click rates without tricks or black-hat methods that could get your account suspended.
Why emails go to spam and how to stop it
Spam filters do not look at content alone. They evaluate technical parameters such as SPF, DKIM, and DMARC records on your domain, the reputation of the IP address you send from, the complaint rate, and recipient engagement. If only 100 people out of 1,000 click anything in the next 30 days, email providers conclude your messages are not relevant and start routing them to spam.
The practical fix is list segmentation. Instead of sending the same email to everyone, split subscribers by behavior: those who opened your last five emails are active, those who have not opened anything in three months are inactive. Send to active subscribers regularly. Run a re-engagement campaign for the inactive ones. If that does not work, remove them from the list without regret.
- Set up SPF, DKIM, and DMARC records on your domain before your first send
- Use a sending subdomain separate from your main domain
- Never buy lists, grow contacts organically only
- Always include a clear and easy unsubscribe link, hiding it increases complaint rates
- Warm up a new sending account by gradually increasing volume over the first four to six weeks
Subject line: 3 seconds to decide everything
The subject line is the only thing the recipient sees before deciding to open or delete. Strong subjects are short (40 to 50 characters), specific, and address the recipient directly. 'New products available' is invisible. 'Here are 3 reasons other customers keep coming back' is considerably stronger, even without personalization.
Preheader text is underrated. It is the short snippet that appears after the subject line in the inbox before the email is opened. Instead of leaving it blank or repeating the subject, use it as a second headline. A strong subject paired with a smart preheader can lift your open rate by 10 to 20 percentage points.
- A/B test subject line variants on 20 percent of the list before sending to everyone
- Avoid trigger words like 'free', 'click now', 'earn money' that activate spam filters
- Use specific numbers: '5 steps' or 'in 20 minutes' always outperform vague phrases
- Personalization in the subject helps, but only if the data point is accurate and relevant
Email marketing you do not measure is like a shop with no cash register: things might come in, but you have no idea how much or why.
Design and content that drive clicks
The biggest design mistake in email is too much content. One email, one message, one CTA (call to action). When you give a reader five different options, they choose none. Decide on the single action you want them to take after reading: a purchase, a registration, reading an article, or booking a call.
Regarding HTML versus plain text: HTML emails with visuals look polished, but plain text or minimal HTML often delivers better deliverability and feels more personal. Test both formats with your audience. Many companies are surprised to discover their subscriber base responds better to the simpler format.
Frequency and timing: when to send
There is no single answer to 'what is the ideal time to send an email,' but there is a solid process for finding out. For B2C brands, Tuesday through Thursday between 8 and 10 in the morning and between 7 and 9 in the evening are a reasonable starting point for testing. For B2B, early morning or before lunch on business days tends to work better because buying decisions get made during working hours.
Frequency is individual. Two to four emails per month is a reasonable ceiling for most brands that do not have daily relevant content. If you push emails every day without reason, unsubscribe rates climb. If you send too infrequently, subscribers forget why they signed up and mark you as spam when you reappear.
Metrics that tell the truth
Open rate is an indicator, but it is not everything. Since Apple Mail Privacy Protection began affecting tracking at scale, open rate has become less reliable. Focus instead on click-through rate (CTR), conversion rate, revenue per email, and unsubscribe rate. If CTR regularly falls below one percent, either the content is not relevant to your audience or the audience is fatigued.
Every month, analyze which emails drove the most clicks and revenue and ask yourself why. Was it the topic, the format, the offer, or the send time? The answer to that question is your next strategy.
- Track CTR as your primary metric, not just open rate
- Set up conversion tracking from email click to purchase in Google Analytics 4
- Measure revenue per subscriber on a monthly basis to see the trend
- Track list growth rate: are you losing subscribers faster than you are adding them
Automation that sells while you sleep
Once-built automated flows are the most profitable part of email marketing. A welcome sequence for new subscribers, an abandoned cart email for e-commerce, a post-purchase sequence that builds loyalty, a win-back campaign for inactive subscribers, and a birthday email that can achieve open rates up to 50 percent. Each of these flows works 24 hours a day and requires no involvement from you after the initial setup.
The izreklamiraj.me team builds, tests, and optimizes complete email funnels for clients, from tool selection to writing every message in the sequence. If your emails are currently landing in spam or opening at half the rate they should, it is time for a serious conversation.
Izreklamiraj.me offers a complete email marketing service: from technical setup of domain authentication and tool selection, to copywriting, template design, and building automated flows. We work with brands sending 1,000 emails a month and with those sending a million. With 10-plus years of experience and a team that monitors every change in email provider algorithms, we make sure your messages reach the inbox, not the spam folder. Visit izreklamiraj.me and book a free consultation.
