How to Send Email Attachments And Best Practices to Follow

ByNupur Mittal


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Adding attachments to an email can be a valuable communication tool. You can convey and showcase the information you can't put in the email body, like your portfolio work.

But, attachment in email suffers from many drawbacks that might cause problems for you. But we are here to help. We will discuss the major pitfalls of email attachments and best practices to leave a great impression on your recipients.

Table of contents

What is an email attachment?

An email attachment is a file that is sent along with an email message. Attachments can be any type of file, such as documents, images, or videos, and used for sharing information between individuals or teams. Email services have limits on the size of attachments that can be sent.

There are different formats to showcase your attachments such as .doc, .pdf, .jpeg, .xls, etc.

For example, if you want to showcase your work to potential clients, you can add your portfolio to your cold email. That portfolio file will be the email attachment.

What types of email attachments can you send?

Different types of attachments you can send in the email are

  • .doc or .docx: For sending text files with images. For example, MS Word and Google Docs
  • .pdf: Sending a formatted text with images that the recipient can easily access irrespective of the operating system, application software, and hardware.
  • .ppt or .pptx: Use this format to send slideshows and presentations.
  • .xls: For sending database in a row and column format. For example, Excel sheets or google sheet files.
  • .png, .jpeg, or .gif: Use this format to send static and animated images.

How to write & send an email with an attachment

The steps to writing an email and attaching files are similar across email clients with slight variations. We will discuss the steps to write and send emails with attachments in Gmail and Outlook to give you an overview.

Steps to send emails with attachments in Gmail (PC)

  1. On your PC, go to Gmail.

  2. Click Compose, a pencil-like icon in the top left corner.

  3. After composing your draft, click Attach.

  4. Choose the files you want to upload.

  5. Click Open.

  6. Then preview your emails and send it.

Steps to send emails with attachments in Outlook

  1. On your PC, go to Outlook.

  2. Click New Message.

  3. After composing your draft, click Attach. You can find this option at the top of emails and the button near the send button.

  4. Choose from the dropdown:

    • Browse this computer: To upload files from your computer

    • Browse cloud locations: Upload files in your OneDrive

    • Upload and share: Select the file from your devices and share it to the recipient's OneDrive folder.

Drawbacks of sending attachments in emails

Here are some of the drawbacks of sending emails with attachments that you should know about:

1. Most phishing attacks happen via attachments

Email attachments are the main method attackers use to carry out phishing activities and deliver malicious programs to your devices. They use social engineering to manipulate you to open an attachment that might infect your device when you click on it or download it. There are measures you must take to avoid such scenarios.

2. Limited email attachment size across email clients

Email clients limit the maximum attachment size you can send or receive to avoid overloading the email servers. If an email server is overloaded, then it ceases to work smoothly. Such restrictions may limit the file size you can send via email.

Maximum email attachment sizes for the most widely used email clients are given in the table:

Email clients Maximum file size limit
Gmail 25 MB
Microsoft Outlook 20 MB
Yahoo Mail 25 MB
iCloud Mail 20 MB

3. Attachments may trigger spam filters

Since attackers use attachments to deploy phishing attacks, many spam filters detect emails with attachments as spam and land them in the spam folder. But, such incidents occur when you send an email with attachments in bulk or use spam trigger words as attachment names.

If your emails land in spam, lower deliverability and thus reduced open rates and click-throughs.

Let's discuss best practices for sending attachments in emails to deal with these drawbacks.

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Best practices to follow while sending email with attachments

Before sending attachments in emails, consider these best practices:

• Use cloud storage to send large file sizes

If you send attachments that exceed the limit supported by email clients, then use the following methods to send them:

Zip it

One of the easiest ways to send large files or a collection of little files is to compress them. Doing so won't affect the file but only reduce the overall size to send it easily.

On your PC, right-click, and you'll see an option to 'compress.' It will create a compressed file with the same name and a .zip extension. You can even create subfolders within the same folder and then zip it.

Share via Google drive link

While composing an email, you get an option to attach Google drive links to your emails. This way, you can send emails that exceed the 25MB limit by Gmail. You can either attach a link that will lead to the file in the Google Drive folder.

OneDrive: For Outlook users

Upload your files in OneDrive if you use Outlook to send attachments exceeding the 20 MB limit.


Dropbox is another handy tool you can use to send large attachments. Upload your files to your Dropbox account, and with the Dropbox extension, you will get the option to attach links within the email. With a free Dropbox account. You can send files of sizes up to 2 GB.

iCloud Mail Drop for Apple users

If you are an Apple mail user, the iCloud Mail Drop can help you send file sizes up to 5 GB. When you send a file size of more than 20 MB, Maildrop automatically comes in. It uploads the file to an iCloud email server, attaches a link, and creates a link. The link will auto-expire after 30 days.

If you can, add links to the source instead of a file. It will navigate users to a webpage where they can easily access the entire content. Adding links also reduces the probability of landing in the spam folder.

• Use an accessible file format

If you send a word file, the recipient needs to have Microsoft Word to view or edit that file. If they don't have it, accessing your files will be difficult. So, use a format that is easily accessible, such as PDFs. Also, having an interactive PDF that helps you provide analytics gives you more insight into what elements of PDF are bringing in more conversion. However, if your file isn’t in that format, you can use tools to convert it. For example, you can convert Google Docs to PDF.

• Name email attachments properly

You should name email attachments so that recipients know what is in the file and avoid spam filters. We have a few suggestions to do that:

  • Avoid using long names.
  • Don't use special characters or emojis such as *, ", #, @, ✔, ➕, etc.
  • Give a descriptive file name. Avoid: 4565_Finalcontent_21. Use: Contentbrief_(date)

Wrap up

Sending email attachments can help you convey valuable information, but you should do it with precaution. Like your email copy, files should also offer information and add value.

Recipients should be clear about what they can expect when they open the file. And whenever possible, use links instead of a file to reduce the chances of landing in the spam folder.

What should you do next?

Thanks for reading till the end. Here are 3 ways we can help you grow your business:


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