The phrase "a message that appears" is correct and usable in written English.
You can use it when describing a message that is visible or displayed in a particular context, such as in software, notifications, or communications.
Example: "After clicking the button, a message that appears will confirm your action."
Alternatives: "a message that shows" or "a message that is displayed."
The attachment carries a message that appears beneath a fluttering American flag: "As New Yorkers, G.T.N. is proud that America is rebuilding.
But today, as long as people have the correct e-mail address, they can send a message that appears instantaneously on an executive's personal computer.
Yet now, when Labour requires a champion thoroughbred, his incessant screeching about the mortal Tory threat to the NHS (not a message that appears to have resonated on Thursday) renders him a one-trick pony.
To ensure that Uncle Joe or Aunt Mary doesn't keel over in shock after receiving a message that appears to have come from the great beyond, each recipient must click on a hyperlink to view the message.
The latest wrinkle in this style of attack is "ransomware" — a program that encrypts your hard drive and sends you a message that appears to come, for example, from the F.B.I.'s Cyber Division, saying that it has detected child pornography or pirated software on your computer and instructing you where to send money, in order to unencrypt your data.
But the policy debate has descended into an angry tit for tat, with accusations of twists and distortions, ever since Mr. Obama began accusing Mr. Romney of shipping American jobs overseas while in the private sector — a message that appears to be resonating among some swing-state voters.
Last September, the Nuclear Threat Initiative posted a translation of a message that appeared on the Web and was attributed to Abu Ayyub al-Masri, the leader of Al Qaeda in Iraq.
When he took the stage, a message that appeared on the large screen behind him read, "The reports of my death are greatly exaggerated".
But in a message that appeared Thursday morning on SouthParkStudios.com, the Web site of Mr. Stone and Mr. Parker's company, the studio said that Comedy Central had imposed further changes to the show.
Last month Lil JoJo, an aspiring rapper who had a feud with Chief Keef, was murdered, and afterward a message that appeared to be mocking his death was posted on Chief Keef's Twitter account.
Mr. Bloomberg maintained that higher crime, subpar education and a lack of city services would drive businesses out of the city faster than higher costs, a message that appeared well received at the conference.
