if exists (select * from [dbo].[sysobjects] where [id] = object_id(N'[dbo].[spS_MailAccounts_ForService]') and OBJECTPROPERTY([id], N'IsProcedure') = 1)
	drop procedure [dbo].[spS_MailAccounts_ForService]
GO

create procedure [dbo].[spS_MailAccounts_ForService]
(
	@MinimumInterval int
)
as
begin

begin tran

declare @AccountId int
select top 1
	@AccountId = [AccountId]
from
	(
		select
			[AccountId],
			datediff(s, getdate(), (dateadd(mi, [TimerInterval], [LastCheckedDateTime]))) as [RefreshDifference]
		from
			[dbo].[MailAccounts] with (tablockx, xlock)
		where
			([LockDateTime] is null) and
			([IsActive] = 1)
	) MA
where
	([RefreshDifference] <= @MinimumInterval)
order by
	[RefreshDifference]

update MailAccounts
set
	LockDateTime = getdate()
where
	(AccountId = @AccountId)

commit tran

if @AccountId is not null
	exec [dbo].[spS_MailAccounts] @AccountId
end
GO

grant execute on [dbo].[spS_MailAccounts_ForService] to [public]
GO