Mailbox providers

AT&T is one of the largest telecommunication providers in the United States.  The modern AT&T company was created in 1983 as the result of the breakup of the original AT&T telephone monopoly. The breakup of AT&T created numerous regional telephone...

It can sometimes be difficult to know where to start when you see deliverability problems. Whether the deliverability problems are widespread or focused on only a few mailbox providers, these tips can help you determine a cause.  Initial troublesh...

Sending successfully to Comcast and reaching the inbox is highly dependent on your sending reputation and following Comcast’s sending best practice guidelines. Please refer to Comcast's postmaster website for additional detail. Escalation For deli...

Sending successfully to Comcast and reaching the inbox is highly dependent on your sending reputation and following basic sending best practices. While following best practices doesn’t guarantee inbox placement at Comcast, it greatly increases you...

Comcast was founded in 1963 and has two primary businesses: Comcast Cable and NBC Universal. Over the past 50 years, Comcast increased its business footprint in the U.S. and is the largest U.S. cable provider with more than 25 million email subscr...

NetEase, Inc. is a leading Chinese technology company that provides internet services, applications, games, and other technologies. It is one of China's largest email providers whose brands include: 126 Mail 163 Mail Yeah.net 188.com Infrastruct...

The only mailbox providers able to accept email over Internet Protocol version 6 (IPv6) are: Comcast Gmail Yandex Additional mailbox providers may accept email over IPv6 in the future, but it is not clear when that will happen. 

Germany is an important region for ecommerce and email marketing. The leading mailbox providers in Germany are: United Internet (gmx, web.de, 1&1 and mail.com)  37.2% of active mailboxes. Gmail (21.4%) Microsoft (9.0%) T-online (7.5%) Yahoo! (6.3...

Tencent QQ is a leading Chinese instant messaging service and web portal created by Tencent. Its email service QQMail competes with NetEase as one of the largest email providers in China. Infrastructure  Region Asia Pacific (APAC): China ...

China is the world’s most populous country, with 1.4 billion people. It is the second largest economy in the world with a 2019 Gross Domestic Product (GDP) of approximately $14 trillion. China continues to modernize rapidly, making the Chinese mar...

UOL is Brazil's largest internet content and technology services company. Mailbox provider infrastructure  Region Latin America: Brazil Domains uol.com.br; hosted domains Connection and throughput UOL does not disclose connection...