Email Client Feature Support Rankings

Last modified: 3 May 2026

Can I Email? breaks down email features by the clients that support them. These features come with intrinsic value, which can be broken up into three buckets. Accessibility, performance, and internationalization (i18n).

This page lists the number of features supported in each category by each email client.

Email client ranks by category

The below outlines the three categories of accessibility, performance, and internationalization with the respective email clients that support them.

Accessibility (37 tested features)

These features are key to enabling assistive technology such as screen readers to be able to ingest email content. Email clients that support a majority of these features give email creators all opportunities to create accessible emails for their subscribers.

Tested features

Number of features	Email Clients
34/37	Apple Mail (MacOS)
31/37	Apple Mail (iOS) Samsung Email (Android)
27/37	ProtonMail (Desktop webmail) ProtonMail (iOS)
25/37	Outlook (Android) Mozilla Thunderbird (MacOS)
24/37	ProtonMail (Android)
23/37	SFR (Desktop webmail) GMX (iOS)
22/37	Outlook (MacOS) Outlook (iOS) SFR (iOS)
21/37	SFR (Android) WEB.DE (iOS)
20/37	Outlook (outlook.com) Fastmail (Desktop webmail)
19/37	LaPoste.net (Desktop webmail)
17/37	Gmail (Desktop webmail) AOL (Android)
16/37	Yahoo! Mail (Desktop webmail) Yahoo! Mail (Android) AOL (Desktop webmail) Mail.ru (Desktop webmail) 1&1 (Desktop webmail)
15/37	Gmail (iOS) Gmail (Android) Gmail (Mobile webmail)
14/37	Yahoo! Mail (iOS)
12/37	AOL (iOS) GMX (Android)
11/37	Outlook (Windows) Orange (Desktop webmail) Orange (Android) HEY (Desktop webmail)
10/37	Orange (iOS) GMX (Desktop webmail) WEB.DE (Android) 1&1 (Android)
9/37	WEB.DE (Desktop webmail)
8/37	Outlook (Windows mail)
4/37	Free.fr (Desktop webmail)
2/37	T-online.de (Desktop webmail)
0/37	Mozilla Thunderbird (Windows)

Performance (6 tested features)

These features are key to the success of email rendering and loading.

Tested features

Number of features	Email Clients
6/6	Apple Mail (iOS) Samsung Email (Android) SFR (Desktop webmail)
5/6	Apple Mail (MacOS) LaPoste.net (Desktop webmail)
4/6	Outlook (MacOS) Outlook (outlook.com) Outlook (iOS) Outlook (Android) Mozilla Thunderbird (MacOS) SFR (iOS) SFR (Android) Orange (Desktop webmail) HEY (Desktop webmail) GMX (iOS) WEB.DE (iOS)
3/6	Yahoo! Mail (Desktop webmail) Yahoo! Mail (iOS) Yahoo! Mail (Android) AOL (Desktop webmail) AOL (iOS) AOL (Android) Orange (iOS) Orange (Android) ProtonMail (Desktop webmail) ProtonMail (iOS)
2/6	Outlook (Windows mail) ProtonMail (Android) Mail.ru (Desktop webmail) Fastmail (Desktop webmail) GMX (Android) WEB.DE (Android) 1&1 (Desktop webmail) 1&1 (Android)
1/6	Gmail (Desktop webmail) Gmail (iOS) Gmail (Android) Gmail (Mobile webmail) Outlook (Windows) Mozilla Thunderbird (Windows) Free.fr (Desktop webmail) GMX (Desktop webmail) WEB.DE (Desktop webmail)
0/6	T-online.de (Desktop webmail)

Internationalization (39 tested features)

Certain aspects of HTML and CSS are limited in their ability to translate across many languages. This category of features outlines those that are beneficial to internationalization (I18n) which would allow for developers the freedom to create semantic HTML in languages aside from English.

Tested features

Number of features	Email Clients
37/39	Apple Mail (MacOS) Apple Mail (iOS) ProtonMail (Desktop webmail) ProtonMail (iOS) ProtonMail (Android)
33/39	Mail.ru (Desktop webmail)
30/39	Samsung Email (Android)
26/39	GMX (iOS) WEB.DE (iOS)
22/39	Mozilla Thunderbird (MacOS) SFR (Desktop webmail) GMX (Android) WEB.DE (Android) 1&1 (Desktop webmail) 1&1 (Android)
20/39	SFR (iOS)
19/39	SFR (Android)
18/39	Outlook (iOS) LaPoste.net (Desktop webmail)
16/39	Outlook (outlook.com) Fastmail (Desktop webmail)
15/39	Outlook (MacOS) Outlook (Android)
13/39	Gmail (Desktop webmail) HEY (Desktop webmail)
10/39	Gmail (iOS) AOL (iOS)
9/39	Gmail (Android) Gmail (Mobile webmail) Yahoo! Mail (Desktop webmail) Yahoo! Mail (iOS) Yahoo! Mail (Android) AOL (Desktop webmail) AOL (Android)
8/39	Orange (iOS) Orange (Android)
6/39	Orange (Desktop webmail)
4/39	GMX (Desktop webmail) WEB.DE (Desktop webmail)
3/39	Outlook (Windows) Outlook (Windows mail)
1/39	T-online.de (Desktop webmail) Free.fr (Desktop webmail)
0/39	Mozilla Thunderbird (Windows)

Features per email client

Gmail (Desktop webmail)

Category	Supported	Partial	Unsupported	Total
Accessibility	17(view)	2(view)	18(view)	37
Internationalization	13(view)	1(view)	25(view)	39
Performance	1(view)	2(view)	3(view)	6

Gmail (iOS)

Category	Supported	Partial	Unsupported	Total
Accessibility	15(view)	3(view)	19(view)	37
Internationalization	10(view)	4(view)	25(view)	39
Performance	1(view)	2(view)	3(view)	6

Gmail (Android)

Category	Supported	Partial	Unsupported	Total
Accessibility	15(view)	5(view)	17(view)	37
Internationalization	9(view)	7(view)	23(view)	39
Performance	1(view)	2(view)	3(view)	6

Gmail (Mobile webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	15(view)	3(view)	19(view)	0	37
Internationalization	9(view)	4(view)	25(view)	1(view)	39
Performance	1(view)	2(view)	3(view)	0	6

Outlook (Windows)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	11(view)	4(view)	21(view)	1(view)	37
Internationalization	3(view)	5(view)	31(view)	0	39
Performance	1(view)	0	5(view)	0	6

Outlook (Windows mail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	8(view)	3(view)	22(view)	4(view)	37
Internationalization	3(view)	5(view)	30(view)	1(view)	39
Performance	2(view)	0	4(view)	0	6

Outlook (MacOS)

Category	Supported	Partial	Unsupported	Total
Accessibility	22(view)	7(view)	8(view)	37
Internationalization	15(view)	1(view)	23(view)	39
Performance	4(view)	0	2(view)	6

Outlook (outlook.com)

Category	Supported	Partial	Unsupported	Total
Accessibility	20(view)	7(view)	10(view)	37
Internationalization	16(view)	0	23(view)	39
Performance	4(view)	0	2(view)	6

Outlook (iOS)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	22(view)	2(view)	11(view)	2(view)	37
Internationalization	18(view)	1(view)	20(view)	0	39
Performance	4(view)	0	2(view)	0	6

Outlook (Android)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	25(view)	4(view)	7(view)	1(view)	37
Internationalization	15(view)	1(view)	23(view)	0	39
Performance	4(view)	0	2(view)	0	6

Yahoo! Mail (Desktop webmail)

Category	Supported	Partial	Unsupported	Total
Accessibility	16(view)	5(view)	16(view)	37
Internationalization	9(view)	3(view)	27(view)	39
Performance	3(view)	0	3(view)	6

Yahoo! Mail (iOS)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	14(view)	4(view)	17(view)	2(view)	37
Internationalization	9(view)	3(view)	27(view)	0	39
Performance	3(view)	0	3(view)	0	6

Yahoo! Mail (Android)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	16(view)	5(view)	15(view)	1(view)	37
Internationalization	9(view)	3(view)	27(view)	0	39
Performance	3(view)	0	3(view)	0	6

Apple Mail (MacOS)

Category	Supported	Partial	Unsupported	Total
Accessibility	34(view)	3(view)	0	37
Internationalization	37(view)	1(view)	1(view)	39
Performance	5(view)	1(view)	0	6

Apple Mail (iOS)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	31(view)	0	4(view)	2(view)	37
Internationalization	37(view)	1(view)	1(view)	0	39
Performance	6(view)	0	0	0	6

AOL (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	16(view)	3(view)	16(view)	2(view)	37
Internationalization	9(view)	3(view)	27(view)	0	39
Performance	3(view)	0	3(view)	0	6

AOL (iOS)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	12(view)	2(view)	18(view)	5(view)	37
Internationalization	10(view)	2(view)	24(view)	3(view)	39
Performance	3(view)	0	3(view)	0	6

AOL (Android)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	17(view)	2(view)	14(view)	4(view)	37
Internationalization	9(view)	2(view)	25(view)	3(view)	39
Performance	3(view)	0	3(view)	0	6

Mozilla Thunderbird (MacOS)

Category	Supported	Unsupported	Untested	Total
Accessibility	25(view)	7(view)	5(view)	37
Internationalization	22(view)	0	17(view)	39
Performance	4(view)	1(view)	1(view)	6

Mozilla Thunderbird (Windows)

Category	Supported	Untested	Total
Accessibility	0	37(view)	37
Internationalization	0	39(view)	39
Performance	1(view)	5(view)	6

Samsung Email (Android)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	31(view)	1(view)	2(view)	3(view)	37
Internationalization	30(view)	2(view)	7(view)	0	39
Performance	6(view)	0	0	0	6

SFR (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	23(view)	2(view)	6(view)	6(view)	37
Internationalization	22(view)	0	1(view)	16(view)	39
Performance	6(view)	0	0	0	6

SFR (iOS)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	22(view)	1(view)	8(view)	6(view)	37
Internationalization	20(view)	0	1(view)	18(view)	39
Performance	4(view)	0	2(view)	0	6

SFR (Android)

Category	Supported	Unsupported	Untested	Total
Accessibility	21(view)	7(view)	9(view)	37
Internationalization	19(view)	1(view)	19(view)	39
Performance	4(view)	1(view)	1(view)	6

Orange (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	11(view)	2(view)	12(view)	12(view)	37
Internationalization	6(view)	2(view)	10(view)	21(view)	39
Performance	4(view)	0	2(view)	0	6

Orange (iOS)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	10(view)	2(view)	13(view)	12(view)	37
Internationalization	8(view)	2(view)	8(view)	21(view)	39
Performance	3(view)	0	3(view)	0	6

Orange (Android)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	11(view)	2(view)	9(view)	15(view)	37
Internationalization	8(view)	2(view)	6(view)	23(view)	39
Performance	3(view)	0	2(view)	1(view)	6

ProtonMail (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	27(view)	3(view)	4(view)	3(view)	37
Internationalization	37(view)	1(view)	0	1(view)	39
Performance	3(view)	1(view)	2(view)	0	6

ProtonMail (iOS)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	27(view)	1(view)	5(view)	4(view)	37
Internationalization	37(view)	0	1(view)	1(view)	39
Performance	3(view)	1(view)	2(view)	0	6

ProtonMail (Android)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	24(view)	1(view)	5(view)	7(view)	37
Internationalization	37(view)	0	1(view)	1(view)	39
Performance	2(view)	1(view)	2(view)	1(view)	6

HEY (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	11(view)	3(view)	13(view)	10(view)	37
Internationalization	13(view)	0	5(view)	21(view)	39
Performance	4(view)	0	2(view)	0	6

Mail.ru (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	16(view)	3(view)	14(view)	4(view)	37
Internationalization	33(view)	0	6(view)	0	39
Performance	2(view)	0	4(view)	0	6

Fastmail (Desktop webmail)

Category	Supported	Unsupported	Untested	Total
Accessibility	20(view)	6(view)	11(view)	37
Internationalization	16(view)	2(view)	21(view)	39
Performance	2(view)	4(view)	0	6

LaPoste.net (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	19(view)	1(view)	6(view)	11(view)	37
Internationalization	18(view)	0	1(view)	20(view)	39
Performance	5(view)	0	1(view)	0	6

T-online.de (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	2(view)	1(view)	4(view)	30(view)	37
Internationalization	1(view)	0	0	38(view)	39
Performance	0	0	0	6(view)	6

Free.fr (Desktop webmail)

Category	Supported	Unsupported	Untested	Total
Accessibility	4(view)	1(view)	32(view)	37
Internationalization	1(view)	0	38(view)	39
Performance	1(view)	0	5(view)	6

GMX (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	10(view)	2(view)	19(view)	6(view)	37
Internationalization	4(view)	2(view)	28(view)	5(view)	39
Performance	1(view)	0	4(view)	1(view)	6

GMX (iOS)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	23(view)	0	1(view)	13(view)	37
Internationalization	26(view)	1(view)	0	12(view)	39
Performance	4(view)	0	1(view)	1(view)	6

GMX (Android)

Category	Supported	Unsupported	Untested	Total
Accessibility	12(view)	12(view)	13(view)	37
Internationalization	22(view)	5(view)	12(view)	39
Performance	2(view)	3(view)	1(view)	6

WEB.DE (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	9(view)	1(view)	18(view)	9(view)	37
Internationalization	4(view)	2(view)	28(view)	5(view)	39
Performance	1(view)	0	4(view)	1(view)	6

WEB.DE (iOS)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	21(view)	0	0	16(view)	37
Internationalization	26(view)	1(view)	0	12(view)	39
Performance	4(view)	0	1(view)	1(view)	6

WEB.DE (Android)

Category	Supported	Unsupported	Untested	Total
Accessibility	10(view)	11(view)	16(view)	37
Internationalization	22(view)	5(view)	12(view)	39
Performance	2(view)	3(view)	1(view)	6

1&1 (Desktop webmail)

Category	Supported	Partial	Unsupported	Untested	Total
Accessibility	16(view)	1(view)	4(view)	16(view)	37
Internationalization	22(view)	0	5(view)	12(view)	39
Performance	2(view)	0	3(view)	1(view)	6

1&1 (Android)

Category	Supported	Unsupported	Untested	Total
Accessibility	10(view)	11(view)	16(view)	37
Internationalization	22(view)	5(view)	12(view)	39
Performance	2(view)	3(view)	1(view)	6