Email Attachment Too Large? 6 Ways to Send Big Files by Email

You've written the perfect email, attached the file, clicked Send — and got bounced back with "Message size exceeds the maximum allowed." This is one of the most common email problems. Here's exactly how to fix it and never run into it again.

Email Attachment Size Limits by Provider

Every email provider caps the total message size. The limit applies to the entire email, not just the attachment — and base64 encoding adds roughly 33% overhead, so a 15 MB file becomes ~20 MB inside the email.

Fix 1: Share a Cloud Storage Link (Best Option)

The cleanest solution — upload the file to a cloud service and share a link in your email. The recipient clicks the link and downloads the file directly.

Google Drive (works in Gmail and any email)

1. Go to drive.google.com and upload your file
2. Right-click the file → Share
3. Set access to "Anyone with the link" (or enter specific emails)
4. Click Copy link and paste it into your email

Gmail shortcut: While composing an email, click the Google Drive icon (triangle) in the toolbar. Select your file — Gmail inserts a Drive link automatically.

Microsoft OneDrive (works in Outlook)

1. Upload your file to onedrive.live.com
2. Right-click → Share → Copy link
3. Paste the link into your email

Outlook shortcut: In Outlook, click Attach File, then choose Browse cloud locations. Select your OneDrive file — Outlook attaches it as a share link.

Dropbox

1. Upload the file to Dropbox
2. Hover over the file → click Share → Copy link
3. Paste in your email

Fix 2: Compress the File Before Attaching

Compression can reduce file size dramatically, especially for documents, images, and folders containing multiple files.

Windows

1. Right-click the file or folder
2. Select Send to → Compressed (zipped) folder
3. Attach the resulting .zip file

For better compression, use 7-Zip (free) — it typically achieves 30–50% better compression than the built-in Windows zip.

Mac

1. Right-click (or Control-click) the file or folder
2. Select Compress "[filename]"
3. Attach the .zip file

Images specifically

If you're sending photos, resize them first. A 12-megapixel phone photo can be 5–8 MB; resized to 1920×1080 it drops below 1 MB with no visible quality loss for email viewing. Use squoosh.app (free, browser-based) to compress images quickly.

Fix 3: Use a File Transfer Service

These services are purpose-built for sending large files — no account needed for the recipient:

• WeTransfer — up to 2 GB free; recipient gets a download link by email. Link is valid for 7 days.
• Firefox Send / Filebin — no account required, end-to-end encrypted options
• SendGB — up to 5 GB free

Just upload your file, copy the download link, and paste it into your email body.

Fix 4: Split the File Into Smaller Parts

If you must send the file as an attachment (e.g., for compliance reasons), you can split it into multiple parts:

• 7-Zip: Right-click → 7-Zip → Add to archive → set "Split to volumes" to e.g. 15M
• WinRAR: Add to archive → set volume size

Send each part in a separate email. The recipient must have 7-Zip or WinRAR to reassemble the parts.

Fix 5: Use Apple Mail Drop (Mac / iPhone)

Apple Mail has a built-in feature called Mail Drop that handles attachments up to 5 GB automatically.

1. Compose your email in Apple Mail and attach the large file
2. Click Send — if the attachment is over 20 MB, Apple will prompt you to use Mail Drop
3. Click Use Mail Drop — Apple uploads the file and sends the recipient a download link

Mail Drop links are valid for 30 days. No setup required.

Fix 6: Convert the File to a Smaller Format

Sometimes the easiest fix is changing the file format:

• Word/PowerPoint → PDF: File → Save As → PDF. Usually 30–70% smaller
• High-res images → JPEG at 80% quality: Often 80% smaller with no visible difference
• Video → compressed MP4: Use HandBrake (free) to re-encode at lower bitrate
• Excel with images → remove or compress embedded images: File → Info → Compress Media / Compress Pictures

Why Does the Limit Exist?

Mail servers have limited storage and bandwidth. Large attachments slow down mail queues, consume disk space for every recipient, and can be a vector for malware. Cloud links solve all of this — the file is stored once and recipients download it directly, which is faster and more secure for everyone.

Quick Reference: Which Fix to Use