Have you ever wondered if capitalization in email addresses affects anything? Does it matter if we write [email protected] or [email protected]? Will the email go to the wrong address?
Read on to learn whether emails and domain names are case-sensitive and the right and most effective email format and syntax.
Do Capital Letters Matter in Email?
In most cases, valid email addresses are not case-sensitive. Popular email services such as Gmail, Yahoo, and Outlook do not distinguish between lowercase and uppercase letters in the local part of the address (the part before the “@” symbol).
No matter what email format you use, each letter will be sent to the same recipient:
This makes creating and using emails more convenient because you don’t have to worry about remembering the exact case. However, it is worth noting that some old email servers may be case-sensitive in the local part of the address.
Do Capital Letters Matter in Emails?
For greater security and to avoid confusion, it is better not to resort to email capitalization and use small letters. So, the opinion that email addresses are case-sensitive is wrong, but capitalization in emails does not affect anything.
Possible Consequences of Invalid Email Address Format
Around 25% of users never check their spam folders, so you should avoid hitting the spam folder at all costs.
Source: Zero Bounce
Ignoring the valid email format leads to three major problems: bounced emails, low deliverability rates, and, as a result, a decrease in your sender’s reputation.
1. Bounced Emails
Bounced emails are rejected by the recipient’s server due to formatting errors because of the wrong format, typos in the email address, or an overly long message. Every bounced email is a waste of resources.
2. Deliverability Rates
Deliverability rates are the percentage of emails that reach the recipient’s inbox.
Badly formatted emails are more likely to be flagged by spam filters or sent to the spam folder. If it happens frequently, the reach of campaigns may be significantly reduced.
3. Damage to the Sender’s Reputation
The job of Internet Service Providers (ISPs) is to track the behavior of email senders by detecting and – once your sender’s reputation is critically low – blocking poorly formatted emails altogether or sending them to the spam folder.
The Advantages of Flawlessly Formatted Emails
If your email is properly formatted, besides improving your status as a sender, you will get two other significant benefits:
- Improving marketing performance. Higher delivery rates lead to better campaign performance. The more emails arrive in the inbox, the sooner you will increase website traffic and sales.
- Saving time and resources. Avoiding bounced emails reduces wasted effort and increases efficiency. Formatting emails correctly in advance saves time in the long run and eliminates your frustration.
The Proper Email Address Structure
An email address, like a postal address, indicates the location of a “mailbox” on the Internet.
Here’s a typical email address format:
Source: Mailchimp
We will focus on 2 main parts: the local and the domain part.
Local part
| Domain Part
|
| Meaning
| |
| The username or nickname you choose for your email server
| This is the server or domain address where the mailbox is hosted
|
| Where does it stand?
| |
| Before the “@” symbol
| After the “@” symbol
|
| How long should an email address be?
| |
| Up to 64 characters
| Up to 255 characters
|
| Email address formatting rules
| |
|
|
| Common rules for correct email address format
| |
| |
| The correct format of the email address example
| |
|
|
Here are a few examples of valid email addresses with different email syntax (subdomain, dash, plus, country, etc.):
- [email protected]
- [email protected]
- [email protected]
- [email protected]
- [email protected]
- [email protected]
Special Characters in Email Address Formatting
Perhaps the most common questions are questions like: “Is it allowed to use the $ sign in the address?” or “What about the = in the email address line?”. The answer to this is special symbols.
Special Symbols
Many email servers allow you to use special characters in email addresses. However, for better compatibility and to avoid delivery issues, it is recommended to avoid them whenever possible.
Special Characters Allowed in the Local Email Address Part
| Dot (.) | Separates names in the local part (example: john.doe) |
| Hyphen (-) | Separates words or names (jane-green) |
| Exclamation mark (!) | Some servers allow it, but its use is not recommended (user!123) |
| Dollar sign ($) | Allowed, but may result in being marked as spam (bill$williams) |
| Percent sign (%) | Rarely used, but some servers support it (marketing%team) |
Symbols to avoid (by Google’s policy and accordingly Gmail, the most popular email service):
| Ampersand (&) | Problematic in Gmail, used for filters |
| Equal sign (=) | Not allowed |
| Underscore (_) | There are servers that allow it, but it is better to avoid it in Gmail because the dot is normally used for separation |
| Single quotes (‘) and other quotes | Not allowed, because it leads to difficulties with formatting |
| Indents and other separators | Not allowed |
International Characters and Unicode in Email Address Formatting
Some modern mail servers support international characters using Unicode. This allows you to use characters from different alphabets—Cyrillic, Greek, or Chinese—in the email address. However, the recipient may not see your address if their server does not support Unicode.
Email Address Formatting Best Practices
#1. Keep It Simple and Easy To Read
We recommend using an email name format that is easy to remember and pronounce. Avoid using special characters and limit the number of long words and complex orthographic constructions.
Source: Tenor
#2. Avoid Excessive Use of Dashes and Hyphens
While some numbers or hyphens may be acceptable, overusing them makes an email address difficult to read and remember.
#3. Use a Public Domain
By choosing a domain, you put an emphasis on reliability and prove your professionalism. If you are creating your own domain, make sure it is not complex and related to your name or brand.
#4. Use Email Address Format with Your Name
A personal email format is easier to remember because it helps your recipient build associations between you and your business. The consumer sees your name in the mail and immediately remembers what services you provide.
#5. Check Availability
Before finalizing your email address, make sure it’s not already in use. Use online availability checking tools or contact your email service provider.
Mini-Test, or Criteria for Correct Email Format
Want to know if your email address format is correct?
Look at your existing email and put the “🗸” near the points that describe it:
- Your email address has only one “@” symbol
- The ”before @” local part is less than 64 characters
- The “after @” part is less than 255 characters
- Only special characters supported by the email server are used: “.”, “-”, “_”, “!”, “#”, “%”.
- There are no following symbols: “&”, “$”, “=”, “_”, “‘”, “–”, “+”
- The domain name contains at least one “.” to separate subdomains (e.g., gmail.com).
- Email address does not have any spaces
The result of the test: All checkmarks mean your email format is correct.
Key Takeaways: Does Upper and Lower Case Matter in Email?
Long story short, most servers are not case-sensitive, meaning that “[email protected]” is the same as “[email protected].” This eliminates confusion and ensures that your emails reach your recipients, even if you accidentally use the wrong case.
However, proper formatting is beyond the scope of sensitivity. Using clear and concise addresses with separators improves readability and shows your professionalism.
So why not take a few minutes to check if your email format is correct? A quick review can greatly improve customer communication and help avoid potential rejections due to incorrect email address formats.
Email Marketing Extravaganza at MailCon Show in New York
MailCon is back with a one-day email performance and deliverability conference on July 28th in New York City.
Every attendee will get:
- Productive email marketing sessions reinforced with panels and workshops addressing the most pressing topics for mailers
- Speaking and exhibition opportunities
- Connecting with renowned email marketing professionals and experts
