The decision of an asylum officer to grant or to deny asylum or to refer an asylum application, in accordance with § 208.14(b) or (c), shall be communicated in writing to the applicant. Pursuant to § 208.9(d), an applicant must appear in person to receive and to acknowledge receipt of the decision to grant or deny asylum, or to refer an asylum application unless, in the discretion of the asylum office director, service by mail is appropriate. A letter communicating denial of asylum or referral of the application shall state the basis for denial or referral and include an assessment of the applicant's credibility.