SAN JOSE: A year after unveiling a free e-mail service with a full gigabyte of storage, Google is doubling the capacity of each account and plans to keep bumping up the limit in the future. Once the upgrade takes effect on Friday, Gmail users will be able to store up to 2 gigabytes of e-mail and attachments for each account. Even more capacity will be made available after that as it becomes feasible, the company said. "Our goal is to make sure storage is no longer an issue for Web mail users," said Marissa Mayer, Google's director of consumer Web products. The announcement was made on the first anniversary of the Internet search engine's launch of Gmail, which surprised many users with its generous storage allotment and prompted rivals Yahoo and Microsoft to boost the capacity of their own free Web mail services.